Beach Stones – Page 7

TS2 – HALL OF FAME

This “Hall of Fame” features stones that I have personally collected and/or tumble polished, that I particularly value for some reason. Stones will be added to it from time to time.

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NUMBER ONE: AGATISED FOSSIL CORAL FROM GEMSTONE BEACH (Added 24 February 2023)

The stone when found in June 2020.

The stone after tumble polishing.

Close-up of the polished stone.

The side of the polished stone.

This very rare fossil coral stone was found by me in June 2020 (see “Day Fifteen, Eighth Visit to Gemstone Beach” in this Post). I was fossicking with my sister Helen, who walked over to show me a stone she had found. We were discussing what kind of stone it might be when I looked down and spotted a stone with faint unusual markings. I picked it up, put it in my bag, and continued my conversation. Looking at it carefully later, I saw that the markings were quite distinct, and some internet searching revealed it to be a type of fossil coral. The details of that research are reported in this Post, a contribution to an alphabetical series run by the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils”. Malcolm Luxton, author of “Agates of New Zealand”, has mentioned in that Facebook Group that the stone is “agatised coral”. The stone is 4 cm long, 3 cm wide and 2 cm at its thickest. Upon tumbling, it polished very well, taking an excellent shine. I fossick often at Gemstone Beach, and the nearby stretch of beach on Te Waewae Bay, but have not seen another such stone. I have also not yet heard of any similar stones being found there either.

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NUMBER TWO: MOSSY JASPER FROM SEADOWN BEACH, KAKANUI (Added 24 February 2023)

One side of the stone, when found on the beach.

Other side of stone, when found on the beach.

This is the most colourful and interesting of all the jaspers I have found. I spotted it on the beach in February 2021. I recall clearly how it was just sitting on top of a bunch of smaller stones, wet and glistening in the sun. See the entry for “Day Three, Friday 19 February” in this Post.

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NUMBER THREE: HEMATITE JASPER FROM TIMARU SOUTH (Added 25 May 2023)

The stone when found on the beach.

The stone when found on the beach.

After tumble polishing.

After tumble polishing.

I found this stone on a beach south of Timaru on 6 March 2022. I picked it up just before leaving the beach and initially put it back down because of its size and its battered character. However, after a few steps I went back to pick it up again as I thought it would be a good candidate for tumbling by my friend Tracey Kidd who lives near Christchurch – she has a tumbling barrel larger than my largest 12lb one. Tracey went ahead and tumbled it successfully. The polished stone is 7.5 cm long, 4.5 cm high, and 2.5 cm at its widest tapering to 1 cm at its narrowest. It’s heavy, weighing 20 grams. It has a few small holes in it as it started out in a bit of a mangled condition. But it polished very well, thanks to Tracey’s work. In fact, the shine on it is so good that it is difficult to photograph without reflections interfering, even in bright direct sunlight. Hematite is a dense and relatively hard iron oxide that is quite abundant in nature. Jasper is an opaque variety of cryptocrystalline quartz, and its often brick-red to brownish-red colour is due to the presence of hematite. I have found and tumble-polished quite a few smaller hematite jaspers of various kinds, especially brecciated and orbicular. I have noticed that when a jasper contains significant quantities of the dark silvery kind of hematite, its red is especially intense and bright. This hematite jasper stone, after spending a few months with Tracey, sitting amongst other stones on her table, now resides with me on a cabinet shelf alongside the other members of the Hall of Fame.

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NUMBER FOUR: TRACE FOSSIL IN ARGILLITE FROM GEMSTONE BEACH (Added 8 August 2023)

Tumble-polished trace fossil stone, Gemstone Beach.

This a reasonably small flat trace fossil stone found on Gemstone Beach a few years ago. It is about 3.5 cm tall and 3.5cm wide, and only about 4mm to 6 mm thick. The trace shape on it consists of a number of chevrons in a sinuous J. To my mind, it is an excellent representative of its kind. Such traces are the fossilised burrows or tracks of some animal left in ocean floor sediments in the Permian Era (250 to 300 million years ago). The host rock tends to be argillite. I have found many such stones along the south coast of the South Island, especially between Riverton Aparima and Gemstone Beach at Orepuki, but am aware of them being found elsewhere as well, including the North Island. I tumble polish trace fossil stones lightly, with just one fine grit tumble before a polish tumble, in order to preserve the traces. Note that there are a range of different kinds of trace fossil stones with burrows and tracks in them in New Zealand, including those found along the Kaikoura Coast often referred to as “zoophycos”.

TumbleStone Blog contains a Series of four Posts on these trace fossil stones which records the progress of my research on them – the start of this Series is a Post from July 2019. “The Tattooed Rock, The Trace Fossils…” is a March 2023 Post that effectively provides a brief summary of the Series, along with some additional information. In mid-2020, I compiled a small photo-book “The Trace Fossil Stones of Gemstone Beach”, and the stones often feature in my Calendars (such as the 2020 TumbleStone Calendar). The stones appear regularly in a range of other Posts, from Stones of the Day (such as here, here, and here) to fossick Posts (such as here and here) to alphabetical Series (see here). It is fitting that a representative goes into the Hall of Fame.

HOME – FOSSICKING BEACHES – BEACH STONES – TUMBLE-POLISHING

Index to Facebook Group Alphabetical Series

A is for Amygdaloidal

B is for Botryoidal

C is for (Fossil) Coral

D is for Dendrites

E is for Entrance

F is for Fossil Worm Cast

G is for Green Hydrogrossular

H is for Hematite Jasper

I is for Ichnogenus Protovirgularia

J is for (Picture) Jasper

K is for Kai Iwi Beach Stone

L is for Leithfield Beach Petrified Wood

M is for Muscovite Mica from Joyce Bay

N is for November in the Calendar

O is for Opaque Orepuki Orbicular Jasper

P is for Planet in a Pebble

Q is for Quartzite Stone from Kakanui

S is for Slope Point Stone

T is for Timaru Today

U is for Unusual Variations of Trace Fossil Stones

V is for >>>>>>

W is for Ward Beach ZoophycosCross in a Stone

X is for X-Figures When Veins Cross in a Stone

Y is for Yellow Stone from Kaikoura Coast

Z is for Zoomorphic Shape in Stone

I am a member of the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils”. The Administrators invited members to submit photos each week of a stone, mineral or fossil in their collection that starts with a letter of the alphabet. My first Post was made on 1 May 2021. Since then, I have re-posted each one on TumbleStone, two at a time:

“A” is for “Amygdaloidal”
“B” is for “Botryoidal Chalcedony”
“C” is for “(Fossil) Coral”
“D” is for “Dendrites”
“E” is for “Entrance”
“F” is for “Fossil Worm Casts”
“G” is for “Green Hydrogrossular Garnet”
“H” is for “Hematite Jasper”
“I” is for “Ichnogenus Protovirgularia”
“J” is for “(Picture) Jasper”
“K” is for “Kai Iwi Beach Stone”
“L” is for “Leithfield Beach Petrified Wood”
“M” is for “Muscovite Mica from Joyce Bay”
“N” is for “November in the Calendar”
“O” is for “Opaque Orepuki Orbicular Jasper”
“P” is for “Planet in a Pebble”
“Q” is for “Quartzite Stone from Kakanui”
“R” is for “Riverton Rocks Red Rock”
“S” is for “Slope Point Stone”
“T” is for “Timaru Today”
“U” is for “Unusual Variations of Trace Fossil Stones”
“V” is for “The Chevron Shape of Trace Fossils”
“W” is for “Ward Beach Zoophycos”
“X” is for “X-figures when veins cross in a stone”
“Y” is for “Yellow Beach Stone from Kaikoura Coast”
“Z” is for “Zoomorphic Shape in Stone”

Another South Island Fossicking Trip, February/ March 2021 – Last Two Days (Leithfield Beach, Kaikoura Coast, Ward Beach)

The first Post in this Series is here.

Day 23, Thursday 11 March – Leithfield Beach and Kaikoura Coast. I spent nearly three hours on Leithfield Beach this morning on a cloudy day threatening rain, but the rain moved across to the north of me.

I always walk southwards from where I park the car at Leithfield Beach to fossick around these old stormwater pipes. The person near them provides scale.

Looking out to sea over the old stormwater pipes.

Leithfield Beach stones this morning, looking north. There is rain in the distance which fortunately did not come my way.

Leithfield Beach stones.

Probably a spotted shag.

Here are seven jaspers found on Leithfield Beach – I especially like the yellow in them. The seven go from the most to the least yellow, the least red to the most red. These stones are often less smooth than the ones I collect at Gemstone Beach and Kakanui, reflecting the state of most stones on the beach.

And another four stones from this morning:

Small stone. likely to have a lot of chaceldony (agate) in it.

It has been suggested that this is rhyolite.

Very unusual circular pattern on this stone.

I also found an unusual sea-weed like stuff on the beach and posted photos of it on the “New Zealand Lapidary, Rocks, Minerals, Fossils” Facebook Group (see first two photos below).

Found on Leithfield Beach.

Among the stones on Leithfield Beach.

Found on Leithfield Beach.

Stan Wen, a Group member, did some research on it and eventually identified it as the strobila of a certain kind of jellyfish, part of its asexual reproductive process, as illustrated in this diagram from the Seattle Aquarium.

jellyfish33

The Aquarium information states: “When a [jellyfish] polyp strobilates—segmenting its body to reproduce—it releases tiny ephyra into the water. Within a few weeks, a bell appears and the ephyra are considered medusa [adults].”

I then drove to Kaikoura and, in the late afternoon, spent about 40 minutes on the beach near my motel. Here are six stones from that fossick, the first of which has dendrites in it. A dendrite forms when a mineral, starting from a point of origin in the stone, migrates and branches outward.

The beach near my motel, looking back towards the Kaikoura Peninsula.

Kaikoura beach stones, late afternoon.

Dendrites in a stone.

Limestone. Likely to be too soft to polish.

Limestone. Likely to be too soft to polish.

Day 24, Friday 12 March, Last Day – Kaikoura Coast and Ward Beach. I often stop at a little spot on the Kaikoura Coast between Kekerengu and the Waima/Ure River mouth. I am especially interested in the stones there with zoophycos trace fossils. As noted on page 64 of “A Photographic Guide to Fossils in NZ” by H. Campbell et al. (2013), these trace fossils can be found in Muzzle Group geological strata in Marlborough, in fine-grained limestone, marl, mudstone and siltstone, laid down in deep water (over 150 metres), the traces due to burrowing activity by something like an echinoderm (see first photo below for this extract). The stones in the photos below are examples of the range of types of traces I found today, both at my Kaikoura Coast spot and at Ward Beach just over 20 kilometres north. These stones are likely to be too soft to tumble polish well so I left many of them on the beach.

Page 64 of “A Photographic Guide to Fossils of New Zealand” by Hamish Campbell et al. (2013).

Zoophycos trace fossil. The nested curving chevron-shaped trace is one I find particularly attractive.

Another zoophycos trace fossil from the Kaikoura coast.

Stone from Ward Beach.

Parallel zoophycos.

Another Ward Beach zoophycos.

Intersecting trace fossils.

Less organised and less well-defined, but traces probably as well.

A Ward Beach stone with a variety of zoophycos trace fossils.

Ward Beach stone, where the zoophycos traces are harder than the surrounding stone material so are slightly raised.

Some more photos from my stop on the Kaikoura Coast between Kekerengu and the Waima/Ure River mouth:

The beach between Kekerengu and the Waima/Ure River mouth. Looking south.

The stones on the beach. The white limestone(?) stones stand out.

Gorgeous green stone, maybe quartzite?

This stone looks like one where the burrowing that produced the zoophycos traces ended up producing actual holes in the stone (or the burrows were petrified with softer material and eroded away). Or maybe the burrows were made by a different animal. The other side of this stone is equally interesting (see next photo).

The other side of the previous stone.

About 12 kilometres further north on State Highway 1 is the small village of Ward. Ward Beach is about six kilometres off the main road, to the east, set among spectacular scenery – high hills with steep slopes and a coastline with interesting rock formations. The Ward Beach boulders (concretions) are not far from the car park (maybe 10 minutes walk north), although I did not visit them today. The beach was uplifted by the 2016 Kaikoura earthquake, unveiling the boulders.

The Ward Beach boulders – photo taken during an earlier visit.

Ward Beach boulder.

When I arrived, there were about 6 to 8 people from the WSP company (formerly Opus), a Design, Engineering and Environmental Services Consultancy, picking up rubbish as a community service. One of them showed me a mannikin leg he had found, and I gave him a florescent light tube I had found. For a sense of the beach and its setting, see this web page.

Scenes from Ward Beach today:

Looking towards the Ward Beach car park.

Ward Beach stones.

Ward beach in front of the carpark, lowish tide.

White-faced heron on Ward Beach.

A surfer in high seas, just in front of the car park.

Five of the stones I found today on Ward Beach:

Gorgeous little stone I found at Ward Beach. Could be a quartzite.

Other side of previous stone.

Treasure

My trip back over Cook Strait the next day was uneventful in stark comparison to the sailing of nearly four weeks previously!

Another South Island Fossicking Trip, February/ March 2021 – Days 21 and 22 (Kakanui, Temuka)

See here for the first Post in this Series.

Day 21, Tuesday 9 March – Kakanui. On my last day at Kakanui, I spent four hours on the beach between 10.30 am and 2.30 pm, then later another hour between 6 pm and 7 pm. Great weather and great fossicking!

A couple of oyster catchers moving away from me on the Kakanui beach.

The south end of the beach.

Just past the rocks shown in the previous two photos is this small cove which is often piled high with stones. Can be accessed at low tide or otherwise by climbing over the rocks.

Three sea gulls over the Kakanui beach.

Today’s selection of finds are presented in the order I found them. And I will reverse my usual presentation for each stone – first will come the close-up image then the image of the stone itself. Most of these stones should by now be familiar to those who have read previous Posts in this Series – jasper, quartzite, agate. Here are the first six:

Quartzite?

Like caramel.

Jasper.

Fossil hash stone. One side.

Fossil hash stone. Other side.

Another five finds:

Treasure

Could be a type of fossil hash.

Quartzite?

Dark red jasper?

One side of a small beach agate.

Other side of small beach agate.

And a final five Kakanui finds:

Another fossil hash stone.

Another jasper.

Another beach agate.

Small banded jasper.

Quartzite?

Day 22, Wednesday 10 March – Travel day, driving from Kakanui to Amberley, no beach visits partly due to heavy rain. But I called in on Penny Farmer (and Francis) at Temuka in response to her invitation delivered through the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils”. Penny showed me her stone cutting saws and tumblers and the many interesting rocks and pebbles she has accumulated in her shed and garden. She tends to collect much larger specimens than I do, and one of her fossicking areas is Kakanui. She gifted me a few stones, including these two unpolished cut slices and small jasper (many thanks! and thanks to Francis for an excellent cup of coffee!). The close-up photos of these stones have been “brightened” a little to show more detail (partly because the images were taken in dull conditions).

One of Penny Farmer’s cut slices that she kindly gave to me. Probably jasper.

Another of Penny Farmer’s cut slices that she kindly gave to me.. Again, probably jasper.

A grit-tumbled jasper stone given to me by Penny Farmer.

The last Post in this Series, on Days 23 and 24, is here.

Another South Island Fossicking Trip, February/ March 2021 – Days 19 and 20 (Kakanui, Moeraki Village, Katiki)

See here for the first Post in this Series.

Day 19, Sunday 7 March – Travel day. I drove north from Riverton to Kakanui (near Oamaru), and made a brief reconnaissance visit to Kakanui Beach (planning to spend two days here). I arrived at my favourite Kakanui Beach late afternoon and spent about 30 minutes checking out what stones were around. Here are five that I found:

This reasonably plain whitish quartz stone has this on its side.

Treasure

Limonite prase, a kind of jasper. This one has less holes than most.

Probably stained quartz.

Light coloured quartzite.

Plain beach agate, not a bad size.

Day 20, Monday 8 March – Kakanui, Moeraki Village and Katiki. To start off with today, I spent 3 1/2 hours on the beach near Kakanui.

The stones on the beach near Kakanui this morning.

You can see the wet strip of stones I followed today while fossicking. Looking south.

Looking northwards, towards Oamaru.

I went as far as these rocks, which are about 800 metres along the beach.

I found quite a few of the yellow and red quartzites that I like. I first came across a type of yellow quartzite at Birdlings Flat, near Christchurch, a few years ago and was pleased to discover even more of them appearing in the Kakanui area. Some have some red in them, and some I thought have almost no yellow (or red) at all. Here are 11 of these stones found today, starting with predominantly red ones, moving through to yellow ones then to increasingly plainer ones. Yet all the same type of quartzite, I reckon.

Among the other Kakanui stones I found today were these seven:

Fossil hash stone.

Not sure what might have caused these two flower-like-shapes, either fossils or some mineral process.

And these seven:

Nice sized quartzite.

Treasure

Small quartzite.

Jasper.

Another jasper.

In the afternoon I tracked back south for about 30 kilometres to visit a small beach not far from Moeraki village, a recommendation from Oliver who had earlier introduced me to Slope Point.

One end of the small beach near Moeraki Village.

Looking towards the other end of the beach.

Seagull on the small Moeraki Village beach.

There were seals at both ends of the beach so I did not venture further.

Oliver said I might find some agate there. And I did – botryoidal agate, seam agate, and sea-tumbled beach agate.

Botryoidal agate.

Seam agate, wet.

Beach agate, wet.

Other side of beach agate.

As noted by Jocelyn Thornton on page 11 of “Gemstones”, this form of cryptocrystalline silica is more accurately called “chalcedony”, with “agate” being used for the banded variety (see also Te Ara: The Encyclopedia of New Zealand). The Quartz Page provides a well-considered view on this. However, in New Zealand most varieties of chalcedony are often simply called agate. (Malcolm Luxton in “Agates of New Zealand” refers to some types of non-banded chalcedony as agate, such as those with mineral inclusions.)

Chalcedony is composed of very fine intergrowths of quartz and moganite. It is microcrystalline meaning the crystals are microscopic and cannot be observed by the naked eye. Both quartz and moganite have the same chemical formula SiO2 (silicon dioxide) but different crystal structures. When free from impurities, chalcedony is colourless and transparent. Dependent on impurities introduced during its formation, chalcedony comes in a wide variety of colours including red, yellow, green, blue, purple, grey, and white.

I was astounded to find the piece of botryoidal chalcedony/agate, having never come across it before. It was partly buried in the sand and I missed it first time I walked past. I went back a few paces for some reason to look at something else and noticed it from that direction.

One of the other sides of the botryoidal chalcedony.

Another side of the botryoidal chalcedony.

Held up to the sun.

As one website puts it, “Botryoidal minerals form when many nearby nuclei, specks of sand, dust, or other particles, are present. Acicular or fibrous crystals grow radially around the nuclei at the same rate, appearing as spheres. Eventually, these spheres abut or overlap with those that are nearby.” The Moeraki/Kakanui area is well known to have agate/chalcedony, as indicated on the map of rock collecting sites in Te Ara (see photo on left below). The Otago Rock and Mineral Club have a photo of a botryoidal chalcedony with a movable cap from the Moeraki area and a piece from Moeraki sold last year from the Trevor Gray collection (photos centre and right below).

Source: https://teara.govt.nz/en/map/5113/rock-collecting-sites-in-new-zealand

Source: https://sites.google.com/site/theotagorockandmineralclub/photos-of-nz-rocks-minerals-and-fossils-1

Moeraki area botryoidal chalcedony. Source: https://www.facebook.com/TheFamilyJewelsDunedin/posts/154609632961753

Seam chalcedony or agate is a form of this type of rock where layers build up to fill cracks and cavities in sediments (instead of occurring in holes left by gas bubbles in volcanic rocks). Jocelyn Thornton’s “Gemstones” includes an example on page 11. Craig McGregor has an interest in a particular type of seam agate found on the beaches on the south side of the Moeraki Peninsula. He calls it “Tobacco Agate” because of its very streaky layering. Again, I was astounded to find a good-sized piece of seam agate high up the beach, with very few other stones around it.

“Top” of seam chalcedony, dry.

Seam chalcedony held up to sun.

“Bottom” of seam chalcedony, dry.

“Top” of seam chalcedony, dry.

“Side” of seam chalcedony, wet.

The sea-tumbled beach chalcedony/agate I found might have started off as a seam but through wave action, being rolled against sand and other stones, it became shaped into a rounder form. You can often see tiny “concussion” marks on the surface of beach chalcedony, caused by being slammed into rocks and stones by waves and/or the current. Such marks are most noticeable when the stone is dry.

The beach-tumbled chalcedony I found, dry.

Concussion marks.

After my visit to this small beach near Moeraki Village, I went south another few kilometres to the Katiki Beach North Reserve Rest Stop. I had noticed some stones on the beach there yesterday when driving past. A scattering of stones was to be seen across pa lot of the beach. A 20 minutes fossick turned up a handful of interesting stones, and the potential existed for more, but the afternoon was wearing on and I headed back north to Kakanui and my accommodation.

Katiki Beach, looking north.

Katiki Beach, looking south.

The scatter of stones on Katiki Beach.

Stones on Katiki Beach.

Katiki beach stone.

Katiki beach stone.

Katiki beach stone.

The next Post in this Series, on Days 21 and 22, is here.

Another South Island Fossicking Trip, February/ March 2021 – Days 17 and 18 (Gemstone Beach, Tsunami Alert)

See here for the first Post in this Series.

Day 17, Friday 5 March – Gemstone Beach. I had planned today to spend a few hours on Gemstone Beach. However, the North Island of New Zealand experienced a 7.1 magnitude earthquake at 2.27 am this morning off East Cape, waking many people. A tsunami alert was issued, but then later lifted. At 6.41 am, a 7.4 magnitude earthquake struck near the Kermadec Islands, 1,000 kilometres north-east of the country, followed by an 8.1 magnitude shake two hours later. Due to this new and increased tsunami risk, parts of the North Island coast were evacuated and the rest of New Zealand came under a beach and marine threat advisory that “strong and unusual currents and unpredictable surges near the shore are expected”. (See a newspaper article about this here.)

Even though Gemstone Beach was at the furthest point on the country’s southern coast from the tsunami threat, I decided not to proceed with my fossicking plans. All the alerts and advisories were eventually lifted in the afternoon, although people who ventured onto beaches were told to remain alert and cautious. In the late afternoon, I decided to make a short visit to Gemstone Beach (I spent 50 minutes there) where I kept well away from the waves and fossicked in and near the Taunoa Stream mouth, just 200 metres from the carpark.

The circled area was my fossicking area today. (The tide was further out than this when I was there.) Source: Google Maps.

Stones in the Taunoa Stream.

Stones in the Taunoa Stream.

I bought a booklet called “Orepuki and Surrounds Heritage Trail” from the Riverton Museum (“Te Hikoi”) shop which refers to the naming of Taunoa Stream. John Boultbee was an English sailor who arrived at nearby Pahia in 1826 and lived with the Maori there for a year. “In his journal, Boultbee noted a ‘small kainga Toonau’ (Taunoa). This village/kainga was situated near the mouth of the Taunoa Stream, one kilometre west of Orepuki. Twenty years after Boultbee had written about this village, there was nothing left of the site as the Taunoa Stream had become the sludge channel into which all the [gold] miners dumped their tailings” (page 11).

Here are six of the stones I found during my short visit to the mouth of the Taunoa Stream:

Today’s trace fossil stone, a small one with nicely defined traces.

One of the bigger stones I collected today.

Intriguing!

Other side of previous stone.

Small stone, with raised colourful segments.

This one was even smaller, but fascinating…

Small purple stone.

Previous stone from the top.

Very nice complex stone.

Day 18, Saturday 6 March – Last visit to Gemstone Beach. I managed to spend nearly 6 hours on the beach today, finally tearing myself away at 4 pm. The unsettled sea yesterday and overnight had stirred up the stones a bit, as I found some really interesting ones.

Looking across a bit of a wild sea at Gemstone Beach to the mountains of Eastern Fiordland.

Gemstone Beach further west.

Gemstone Beach waves.

Spot the pink stone…

The pink stone!

Gemstone Beach at the car park.

I decided today to show first of all a photo of a stone which gives some idea of its size in my hand, with the second image then being a cropped version of the first photo to show close-up details of the stone. As a result, the first photo may include glimpses of my gumboot and/or my camera wrist-strap. Here are six of today’s finds:

Unusual light colour, interesting inclusions.

Lots of greys.

Stunning small stone.

Very small stone…

Banded argillite, with some fault lines.

Small but vibrant.

Another eight:

Very small quartz stone.

Trace fossil stone,

Maybe because of the recently unsettled seas, I found more hydrogrossular garnets today than usual. This is the stone most sought after on Gemstone Beach. It is also the fourth of the 13 minerals first identified in New Zealand, having been identified in 1943. Here are six of the stones I found today that probably have hydrogrossular garnet in them:

Stone with hydrogrossular garnet in it.

Small white hydrogrossular garnet.

Slight green tint to this hydrogrossular garnet.

Nice brown hydrogrossular garnet.

The next Post in this Series deals with Days 19 and 20, on the start of my journey back north.

Another South Island Fossicking Trip, February/ March 2021 – Days 15 and 16 (Slope Point, Gemstone Beach)

The first Post in this Series is here.

Day 15, Wednesday 3 March – Slope Point. NOTE – OCTOBER 2023 – Landowners are now refusing access to this beach, so please do not visit there without permission. I spent four hours on a beach near Slope Point today, at low tide. Slope Point is the southernmost bit of land of the South Island, 70 kilometres east of Invercargill. The sea and wind can be ferocious here but today was very calm. I had visited the Point in 2018 but it is located high atop cliffs and I couldn’t see how to get down to any beach.

Slope Point is the southernmost part of the South Island. Source: Google Maps.

A photo taken when I visited Slope Point in 2018.

Slope Point itself is atop high cliffs with large waves pounding at it.

The small beach to the west of Slope Point that I visited with Oliver.

There is a useful page (p.35) on Slope Point in Jocelyn Thornton’s “Gemstones”. It is an area known for rhyolites and petrified wood and other volcanic pebbles and petrified material. Rhyolite is a volcanic rock with a high silica content (obsidian, pumice and ignimbrite are are common varieties of rhyolite). There is a photo of tumble-polished Slope Point rhyolites on Craig McGegor’s website. In 2019, I met Jack Geerlings on Gemstone Beach – he is a long-time rock hound and polisher from Winton. He invited me to visit him to view his collection. He had a number of polished rhyolite stones from Slope Point there.

Jack Geerling’s display of Slope Point rhyolite.

Jack Geerling’s collection.

Part of Jack Geerling’s display of Slope Point rhyolite.

Another part of Jack Geerling’s display of Slope Point rhyolite.

Access to a beach in the Slope Point area is not straightforward but it is well worth the efforts to get down to a beach. Many thanks to Oliver Simpson, contacted through the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils” for a very companionable time and for sharing his knowledge.

Looking at the northeast end of the small beach near Slope Point.

Looking back at where we had to drive to, over a couple of paddocks.

The stones on this Slope Point beach.

In behind the beach is a small lagoon with petrified wood in it.

Petrified wood in the small lagoon.

I found a few interesting stones, some of which were rhyolites, others maybe petrified wood or other material, along with some other kinds of stones like jasper and quartz.

Not sure what kind of stone this is – it could contain small fossils.

Probably rhyolite.

Jasper, I think.

I don’t know what this stone is. It was found by Oliver who generously gave it to me when I admired it.

Probably rhyolite.

Probably rhyolite.

Also probably rhyolite.

Petrified wood:

A hunk of petrified wood on the beach, about 15 cms across.

There are pieces of petrified wood in the rocks – this piece is about 4 cms long.

A lot of the petrified wood here is very dark, common in Southland.

Small piece of petrified wood.

Even smaller piece of petrified wood.

Two of Oliver’s pieces of petrified wood, each about 10-12 cms wide.

Finally, a few more Slope Point beach pebbles:

A type of quartz pebble.

Some kind of fossilised forest floor or??

Maybe a jasper?

Slope Point breccia.

Day 16, Thursday 4 March – 8th visit to Gemstone Beach. I spent four hours here today, around low tide. It was a cooler day, with a stiff wind, 12 degrees to start with. By the end of the four hours, it was sunny, my backpack was heavy, and it was 17 degrees.

Low tide at Gemstone Beach this morning.

Gemstone Beach stones.

This bank of stones is about 4 to 5 metres high.

Gemstone Beach stones.

Here’s six of my interesting finds:

Very unusual construction.

Gorgeous jasper.

Quartz.

Quartzite.

The mauve colour in this stone caught my attention. Probably mineral-stained quartz.

Interesting stone texture.

Another five interesting finds:

The ligh-coloured material is a higher surface than the dark.

Fine veins and pastel colours.

One of the hydrogrossular garnets I found today.

This type of stone can be found from time to time on the southern coast.

After my visit to Slope Point yesterday, I became more aware of rhyolite on Gemstone Beach.

Many stones on the beach are gorgeous but not all can be tumble polished, so I leave them behind. Some are too big or too pitted or too soft. Some examples from today of the “too big” type:

Quartz. Too big to tumble – left on the beach.

Also just a big too big.

Banded argillite. Left on beach as too big for my tumblers.

I wonder if the white material might be agate?? Or quartz?? Close-up next photo. Left on the beach because too big.

Quartz, too big.

Breccia with shell fossil, too big.

The next Post in this Series, for Days 17 and 18, reports on visits to Gemstone Beach but in contrasting circumstances, during a national tsunami alert.

Another South Island Fossicking Trip, February/ March 2021 – Days 13 and 14 (Gemstone Beach, The Beach Past the Back Beach at Riverton)

The first Post in this Series is here.

Day 13, Monday 1 March – 7th visit to Gemstone Beach. This visit lasted 4 1/2 hours, the sky was cloudy but the temperature was warm, and there was little wind. Today’s top four finds:

Not sure whether this might be fossil coral or not.

Other side of previous stone.

Probably banded argillite.

Other side of previous stone.

Another of those purple stones, with interesting inclusions.

Outstanding detail.

I think this is a quartzite. A small stone.

I went onto the beach this morning when the tide was low but starting to come in. Decided to walk westwards further than I normally do. However after two hours I decided to turn back as the waves were starting to get high on the beach. I made it back to the car park just in time. The waves were lapping the cliffs in places, and it wasn’t even fully high tide. Much care needs to be taken at Gemstone Beach as the waves are powerful and the banks of stones can be steep, and the cliffs are right at the back of much of the beach.

Gemstone Beach early on in my visit.

Later, Gemstone Beach with high powerful waves sprinting up the banks of stones. The beach near the car park is more benign though care is always required.

Here are five more of today’s finds:

Today’s “pinkie”.

Banded ignimbrite.

Quite a small stone.

I don’t know what this is.

Probably iron-stained quartz of some sort.

Day 14, Tuesday 2 March – The Beach Past the Back Beach, Riverton – I spent just over an hour at this beach this morning, at low tide, the best time to get around the rocks. (Two years ago I did a Post on some stones from this beach which included a location map.) I walked over a hill to get there, then once on the beach walked back towards the Back Beach, eventually prevented from getting right back to it by high rocks, stopping only 100 to 150 metres from the Back Beach.

The western half of the Beach Past the Back Beach. Tihaka Beach and Colac Bay are a few kilometres further on. Most of this morning’s fossicking was behind me, to the east, amongst the rocks there.

Looking back over the hill I had just come over to get to this beach. The Back Beach is on the other side of the hill.

Stones on the Beach Past the Back Beach.

The start of the rocks at the eastern end of the sweep of the Beach Past the Back Beach.

This was as far as I could go this morning. The small cove that is part of the Back Beach is just around the first large rock on the left.

Lots of patches of stones among the rocks. At high tide, this is under about a metre of water.

Lots of stones can be found in these nooks and crannies. See next photo.

This rock is about 5 to 6 metres high.

There are lots of stones on the Beach Past the Back Beach, many similar to Gemstone Beach but not usually of the same bright colours.

Quartzite, probably.

A different coloured quartzite.

This is a small white hydrogrossular garnet. Not usually found this far east along the coast. I have been told of the rare one turning up here, and have found a couple of lower-quality ones in the past two years.

A thulite stone but not as pink as the ones I have found on Gemstone Beach and at McCracken’s Rest. The pink is due to manganese.

Trace fossil stones (argillite) can be found here (and on other Riverton beaches).

An interesting stone due to its band.

An interesting green.

A complex construction.

Interesting hue of blue.

Returning over the hill to my car, I saw a surfer at the Back Beach and took some photos of him. Looking at one of the photos later, I realised there was a dolphin out there as well. On the way back to where I was staying, I passed a spot where I had seen a foiling wind surfer two days previously. Driving past Henderson’s Bay, a stand up paddle boarder could be seen. Later at the crib at Taramea Bay, a man flew a kite in the stiff wind.

Circled in this photo of the Back Beach surfer is a dolphin.

The dolphin.

The surfer, having caught a wave.

The Henderson’s Bay stand up paddle boarder.

A foiling wind surfer near the Back Beach.

Soneone flying a kite at Taramea Bay, Riverton.

The next Post in this Series can be found here, including a trip to Slope Point.

Another South Island Fossicking Trip, February/ March 2021 – Days 11 and 12 (McCracken’s Rest, Gemstone Beach)

The first Post in this Series is here.

Day 11, Saturday 27 February – This afternoon I spent four hours on the Te Waewae Bay beach, accessed from the lookout at McCracken’s Rest, a small off-road parking area eight kilometres west of Gemstone Beach (Orepuki). The coastline of Te Waewae Bay is 27 kilometres long, with Gemstone Beach near the eastern end.

Te Waewae Bay on Foveaux Strait. Source: Google Maps.

Sign post at McCracken’s Rest.

The red pointer is Grindstone Creek – I walked from McCracken’s Rest to about 400 metres past the Creek’s outlet on the beach. Source: Google Maps.

Pointer is at Grindstone Creek. I walked to the point marked by the black cross (lower right). Source: Google Maps.

Part of an Information Panel at McCracken’s Rest.

There are a number of excellent information panels at McCracken’s Rest.

From McCracken’s Rest I walked east for about two kilometres. The beach is largely a continuation of Gemstone Beach, with many of the stones similar. However, there is a little less diversity and a few more bigger stones. The key to a successful fossick on the beach at McCracken’s Rest is timing – most of the stones are high up the beach and in order to see them wet, you need to be there close to high tide. I recommend the period from about 30 to 60 minutes before high tide through to two hours after. Furthermore, take care! The waves are powerful. This is not a swimming beach. Don’t get caught by a wave. Note: Beach access is difficult at McCracken’s Rest, you have to climb over a fence and go down a steep slope.

Looking back up at the McCracken’s Rest lookout from the beach.

Looking east. Gemstone Beach is right in the left distance, 7 kms away. In the distance (centre) is Pahia Hill.

Looking west, towards the Fiordland mountains.

The waves are powerful – you need to be very careful not to get caught by one.

Stones get kicked up by the waves as they hit the beach.

As the tide gets lower, the stones (left) become dry and dull-looking. The lower part of the beach consists of tiny stones.

Grindstone Creek. I turned around about 400 metres past here.

I collected a range of interesting stones east of McCracken’s Rest. Here are four of the smaller ones:

I also found some more pink thulite stones, both small and large:

A large pink stone – it’s about 15 cms in length. I left it on the beach, far too big for me to tumble polish and too heavy to add to my backpack.

Close-up of large pink stone.

Very small pink stone.

Close-up of very small pink stone.

The big and the small.

A dry pink stone – quite big but as I found it near the end of my walk, I decided to keep it. Next photo is of the same stone wet.

The previous stone, but wet. Very pink. Thulite, with the pink caused by the presence of manganese.

Close-up of previous stone.

A few more stones collected from the beach near McCracken’s Rest:

I found a slightly smaller bright purple stone like this yesterday. This one is even better.

Volcanic? Often these stones are chipped or a fragment has fallen out. This stone is is excellent condition.

I am always attracted to stones with veins like this.

The flash of red caught my eye. My backpack was heavy at this stage and I decided to leave this one on the beach.

Nicely shaped trace fossil stone, unusual colour.

Day 12, Sunday 28 February – Gemstone Beach visit again. Arrived at high tide this afternoon and spent three hours on the beach. Weather was partly cloudy and warm. The waves were lapping the cliffs when I got there so I spent the first 40 minutes on the beach in front of the car park and near the Taunoa Stream.

High tide. Standing a couple of hundred metres west of the carpark, looking at where the Taunoa Stream crosses the beach.

The same part of the beach three hours after high tide.

There were a few other people on the beach. I spoke for a while with a couple from Manapouri who were very interested in the stones on the beach, and another couple from Tauranga who were fossicking for hydrogrossular garnets. I found some more gorgeous stones today, some of them in or near the Taunoa Stream. Here are the two outstanding finds of the day:

Five more of today’s finds:

Gorgeous small jasper.

Small complex-patterned stone.

Small banded ignimbrite.

And the last four of the selection of my finds today:

The inclusion, left centre, caught my eye. See next photo.

Another fascinating small stone.

Small jasper, side a.

Small jasper, side b.

The next Post in this Series describes visits to Gemstone Beach (again!) and to the Beach Past the Back Beach (Riverton).

Another South Island Fossicking Trip, February/ March 2021 – Days 9 and 10 (Gemstone Beach, Tihaka Beach, Garden Bay)

The first Post in this Series is here.

Day Nine, Thursday 25 February – Spent another couple of hours at Gemstone Beach this morning. The day was cloudy but calm, about 12 degrees. The photos that follow are of four stones and the process of discovery – the first photo of each set is of the stone on the beach amongst its surrounds (can you spot what I spotted?), then a closer view of the stone is presented, followed by a copy of the first photo with the stone circled, then finally photos of both sides of the stone.

Can you spot what I spotted?

The stone.

The stone circled.

Iron-stained stone, side a.

Iron-stained stone, side b.

Close-up.

The second stone is a green quartzite:

The section of beach that contained the stone.

The green quartzite on the beach.

The green quartzite.

The next stone is pink, a thulite stone:

In the sand on the edge of a stream.

Thulite is the pink to reddish variety of the mineral zoisite. As Minerals.net reports, “The color of thulite is caused by the element manganese in its composition. Thulite often occurs associated with quartz, and is sometimes mottled with streaks or spots of white quartz.”

The fourth and final stone is of a type often found on Gemstone Beach:

Trace fossils in argillite.

Day Ten, Friday 26 February – Today, on my way to Gemstone Beach I made detours to Tihaka Beach and Garden Bay. These two beaches are to the south of the main road between Riverton and Gemstone Beach. Tihaka Beach is at the eastern end of the six kilometre-long sweep of Colac Bay beach. Many of the stones here are small, many are iron-stained or stained by the tannin of local creeks. Large parts of the beach have very small stones. Many of the types of stones found on Gemstone Beach are not often found here, one exception in my experience being trace fossil stones.

Tihaka Beach is to the right, east of Colac Bay. The red pointer to the left is on Garden Road, Garden Bay being south-west of it. Source: Google Maps.

Tihaka Beach is on Te Araroa.

Looking east – Riverton’s Back Beach is maybe six or seven kilometres further on. few

The stones of Tihaka Beach.

A Tihaka Beach stone, one of the few I pocketed.

Small trace fossil stone from Tihaka Beach.

Small jasper from Tihaka Beach.

I stopped off briefly at “The Trees”, the surfing spot on Colac Bay beach, a couple of kilometres west of Tihaka. The beach stones are largely similar, and I found a small stone of interest there.

Looking back towards Tihaka Beach from “The Trees”.

Colac Bay village from “The Trees”.

Small quartzite stone from “The Trees”.

Twenty kilometres from Tihaka Beach is Garden Bay. Garden Bay is not even on Google Maps, though “Garden Road Southland” is, and the Bay is where the road meets the coast. Used as a quiet bay to launch recreational boats, it is sheltered from the strong swells of Foveaux Strait. Despite the small strips of beach, fossicking is more productive here than at Tihaka Beach. However, again the diversity and richness of Gemstone Beach stones are lacking.