Month: September 2021

“S” is for “Slope Point Stone” and “T” is for “Timaru Today”

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

The following are my Posts for “S” and “T” in the weekly alphabetical series of a Facebook Group I belong to, “New Zealand Lapidary, Rocks, Minerals, Fossils”. The first Posts in this Series can be found here. The Series Index is here.

“S” is for “Slope Point Stone” – This tumble polished stone was collected by me earlier this year at a beach just west of Slope Point in Southland.

I initially thought it might be agatised tree fern. For example, in his book, “Agates of New Zealand”, Malcolm Luxton has a small section on Southland agates, and includes on page 292 a reference to “agatised tree fern sections” (see photo below). Two specimens are shown, one from Slope Point and one from Awarua Bay. The one from Awarua Bay looks very similar to the Slope Point stone I found. Jocelyn Thornton’s booklet, “Gemstones”, refers to this sort of stone on two different pages, the first on “Other Plant Material” (a section that follows ones on Petrified Wood, Agatised Wood and Opalised Wood), the second on “Beach Pebbles – Slope Point” (see photos below, the booklet is also online).

Malcolm Luxton, “Agates of NZ”.
“Agatised tree fern. Awarua Bay”. Page 292 of Malcolm Luxton, “Agates of NZ”.
From Jocelyn Thornton, “Gemstones”. http://www.peterthornton.com/files/nzgemstones.pdf
From Jocelyn Thornton, “Gemstones”. http://www.peterthornton.com/files/nzgemstones.pdf

However, it has been suggested that my initial tentative identification is likely to be incorrect. A member of the Group wrote: “I think the slightly circular patterns are more like spherulites than vascular bundles but that’s just my impression.” This would probably make it more likely that the stone is rhyolite. Either way, this is a very intriguing stone. Slope Point is the southernmost part of the South Island mainland, just a few kilometres west of the better-known Curio Bay (a reserve where you can view a rock platform of trunks of petrified trees from the Jurassic). The beaches just to the west of Slope Point are also known for their petrified wood (much of it black) as well as a range of varieties of rhyolite. See here for an Introduction to Slope Point.

“T” is for “Timaru Today” – One of the stones I found today on a Timaru beach as I was passing by on my way south.

Probably a green quartzite – these are often to be found on this beach. I accessed the beach by turning off State Highway One onto Scarborough Road, just south of Timaru.

Access to the beach is at the end of Scarborough Road, at the start of the Jack’s Point Lighthouse walkway.
Around the first corner of the beach when walking southwards – Jack’s Point lighthouse.
Looking north towards Timaru.

I first visited here in early June, after reading on this Facebook Group about a couple of local fossickers who spend time at this beach.

For the next Post in this Series, see here.

“Q” is for “Quartzite Stone from Kakanui” and “R” is for “Riverton Rocks Red Rock”

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

The following are my Posts for “Q” and “R” in the alphabetical series of a Facebook Group I belong to, “New Zealand Lapidary, Rocks, Minerals, Fossils”. The first Posts in this Series can be found here.

“Q” is for “Quartzite Stone from Kakanui” – The most common colour for this kind of quartzite in this area is yellow, though some have red in them and others, like this one, are mainly a more neutral gray. What I find fascinating with these quartzites is how small clear quartz crystals become apparent in the close-up images.

Side A.
Side B.

This stone is Stone #6 in my blog’s daily series marking the National Lockdown, one of the “projects” I work on to help keep me occupied over this period. For those interested, the Series starts here.

“R” is for “Riverton Rocks Red Rock” – This small thin flat dark-red tumble-polished stone was originally collected from one of the beaches of Riverton Rocks, the area of holiday homes that stretches south along the coast from the Southland town of Riverton/Aparima.

Located 30 kms east of Gemstone Beach (Orepuki) and 40 kms west of Invercargill, Riverton/Aparima is the oldest pakeha settlement in Southland. A whaling station was established there in the mid-1830s with land-based economic activity replacing that by the 1850s. Riverton Rocks (comprising Taramea Bay, Mitchell’s Bay and Henderson Bay – see photos below) became an important seaside holiday destination. My grandparents owned a crib (bach) at Henderson Bay from the late 1950s/early 1960s and I spent many Christmas holidays there.

Riverton Rocks. Source of base photo = http://www.stuff.co.nz/…/5058623/Riviera-of-the-south
Riverton Rocks and Back Beach. Source of base photo = http://atoz-nz.com/location/riverton
The eastern end of Taramea Bay, with Riverton town across the estuary. Source = http://www.newzealand.com/nz/plan/business/riverton-southland/
Mitchell’s Bay, Riverton Rocks. Source = https://southlandnz.com/western-southland/natural-attraction/taramea-bay-mitchells-bay?fbclid=IwAR30MlkXxdY58sdV_mCegwFvjLnnFfh2prtjunXQnzF-EFGNvjRrFF3CZEc
Henderson Bay, Riverton Rocks, my photo.

The Back Beach, at the end of the “Rocks Highway”, faces Stewart Island/Rakiura across the often-stormy Foveaux Strait, and is the best fossicking place close to and east of Gemstone Beach. My very first batch of tumble-polished stones (19 April 2016) had been collected from Riverton beaches.

The Back Beach on a stormy day.
The stones of the Back Beach.
Looking from the Back Beach towards Rakiura/Stewart Island.
My first batch of tumble-polished stones, from Riverton, 19 April 2016.

For the next Post in this Series, see here. For the Series Index, see here.

Oliver’s White Chalcedony Stone from Moeraki Village Area

Oliver Simpson found this stone on a beach near Moeraki Village in North Otago, just a few kilometres from the well-known Moeraki boulders. The stone is probably chalcedony with a white frosted outer layer, likely caused by weathering. One side of it seems to have a thicker layer of white than the other.

Rough stone when wet, side A.
Rough stone when wet, side B.

Oliver and I discussed if we should try tumble polishing the stone to see what was beneath the white. We both liked the white skin and I was skeptical whether tumbling would “improve” it. But Oliver thought it was worth a go, so I took it home and tumbled it for him. I was floored when I saw the results of the first 400 grit tumble! One side was still predominantly white but the other was a revelation, revealing the inside structure of the stone.

Side A, after a 400 grit tumble.
Side B, after a 400 grit tumble.

After consultation with Oliver, I put the stone through another week’s tumble in 400 grit. Not a lot of change occurred, and we discussed whether to try to remove more of the outer layer. We decided that the odd white speck on the “A” side was ok. I went on to polish the stone, before sending it back to Oliver in the mail.

The final polish did not add a lot – the most significant changes occurred with the initial 400 grit tumble. The end product shows, on one side (Side A), what is inside the stone, which also turns out to be translucent.

Side A polished.
Side A polished, with a torch behind it.

The other side (Side B) retained some of the original interesting weathering and its patterns.

Side B polished.
Edge of stone, polished.

Oliver’s Fossil Coral Stone

Oliver on a Slope Point beach, in winter.
Slope Point area. Source: Google Maps.
A Slope Point beach on a fine day.

Oliver Simpson found this stone on a Slope Point beach at the bottom of the South Island. When he first showed it to me, I could see nothing in it. He then pointed to some very faint markings and mentioned “coral”. I don’t know whether the stone warmed in my hand and as a result showed the outlines of the coral septa (radiating plates as seen from above) more clearly, but I could then start to make out the faint shapes distinctive to coral.

Oliver’s fossil coral, before tumbling.
Oliver’s fossil coral, before tumbling.
Oliver’s fossil coral, before tumbling.

A previous Post on fossil coral can be found here.

Oliver’s stone is a rare and enigmatic stone, rare because it is fossil coral, enigmatic because it does not seem to show itself easily in person. Oliver and I discussed whether it would be worth tumbling the stone, to bring out the coral shapes more clearly. I was reluctant to do anything to spoil such a rare specimen, but in the end I agreed to give it a go. I tumbled it in a very fine 600 grit for 9 days to see if any improvement occurred.

After 600 grit tumble.
After 600 grit tumble.

Removal of a very thin surface layer brought out the coral shapes in a brighter white. However, I was not keen to try more as I did not think further “improvement” or clarity could be achieved. So the stone then went into a pre-polish then a pro-polish tumble:

The end result is still enigmatic, and lacks some of the subtle beauty of the original stone. While the shapes of the coral can be seen more clearly, they appear harsh and not always cleanly defined.

Twenty-Four Slope Point Stones Polished for Oliver: Part 2, Stones 11 to 24

At the beginning of August, I finished tumble polishing 24 stones that Oliver Simpson had collected from Slope Point beaches (Southland). Part One looked at Stones #1 to #10. This Post presents images of the remaining 14 stones.

The 24 stones in the first batch I polished for Oliver.
The sign at the top of the cliffs at Slope Point.
Oliver on a Slope Point beach.

Stones #11 and #22 appear to be some kind of fossilised material, maybe fern. Such material has really interesting patterns:

Stone #11, Side A.
Stone #11, Side B.
Stone #22, Side A.
Stone #22, Side B.
Stone #22, Side C.

Stone #15 is a small piece of petrified wood with maybe some chalcedony-agate material in it:

Stone #15, Side A.
Stone #15, Side B.
Stone #15, Side C.
Stone #15, Side D.

Another highly interesting stone is #19, with one dark side and one light side, and with other material within it:

Stone #19, Side A.
Stone #19, Side A.

There are five light-coloured petrified wood stones, with one of them, #21, containing some breccia as well:

Stone #21, Side A.
Stone #21, Side B.
Stone #21, Side C.

The other four light-coloured pieces of petrified wood are Stones #14, #17, #23 and #24:

Stone #14, Side A.
Stone #14, Side B.
Stone #17, Side A.
Stone #17, Side A.
Stone #23, Side A.
Stone #23, Side B.
Stone #24, Side A.
Stone #24, Side B.

There are four dark-coloured petrified wood stones, #12, #13, #16 and #18. Stones #13 and #16 include some interesting white markings:

Stone #13, Side A.
Stone #13, Side B.
Stone #16, Side A.
Stone #16, Side B.

Stones #12 and #18:

Stone #12, Side A.
Stone #12, Side B.
Stone #18, Side A.
Stone #18, Side B.

The remaining stone is #20, a small caramel-coloured one:

Stone #20, Side A.
Stone #20, Side B.

Twenty-Four Slope Point Stones Polished for Oliver: Part 1, Stones 1 to 10

At the beginning of August, I finished tumble polishing some stones that Oliver Simpson had collected from Slope Point beaches (Southland). This is an area known for its black petrified wood, including tree ferns (ponga), and rhyolites. Jocelyn Thornton has a page on Slope Point stones in her booklet “Gemstones” (see page 35 here). Oliver is particularly interested in the petrified wood and often collects large pieces.

The 24 stones in the first batch I polished for Oliver.
Slope Point area. Source: Google Maps.
The sign at the top of the cliffs at Slope Point.
High cliffs and rough sea at Slope Point.

After we did a couple of fossicking trips to Slope Point beaches in June (see my Posts for 12 June and 18 June), Oliver showed me a number of his finds from over the years. I offered to tumble polish a few and he entrusted me with some of his smaller stones, many of them really fascinating. He also gave me to tumble a fossil coral he found at Slope Point and an unusual chalcedony stone from near Moeraki Village in North Otago (these will feature in future posts).

The first batch that I finished tumble-polishing numbered 24 stones (see photo above). Most had started with one or two tumbles in 400 grit, the grit and polish stages all being completed on 8 August. The largest stone, Stone #1, is about 4.5 cms long.

One of the beaches to the immediate west of Slope Point.
A Slope Point beach on a fine day.
Oliver on a Slope Point beach.
Some of Oliver’s rock finds.

Here are the first 10 of these:

#1
#2
#3
#4
#5
#6
#7
#8
#9
#10

Stones #2 and #3 are perhaps the most spectacular and interesting. Stone #2 has a broken pattern of different colours with bright white agate-looking material at the top and bottom:

Stone #2, Side A.
Stone #2, Side B.
Stone #2, top.
Stone #2, bottom.

Stone #3 is an excellent example of fossilised tree fern material. The close-ups reveal exquisite complexity:

Stone #3, Side A.
Stone #3, Side B.

Stone #6 is another with intriguing markings:

Stone #6, Side A.
Stone #6, Side B.

Stones #1, #8 and #10 are similar pieces of petrified wood, very dark in colour for most of the stone but with some brown areas that reveal the wood. Stone #1:

Stone #1, Side A.
Stone #1, Side B.
Stone #1, Side C.

Stone #8 has some interesting areas of wood grain:

Stone #8, Side A.
Stone #8, Side B.
Stone #8, Side C.

Stone #10 has a prominent light-coloured band on one side:

Stone #10, Side A.
Stone #10, Side b.

Finally, four of the stones are petrified wood of different hues but with a light-coloured vein within them. Stones #4 and #5 are similar in having areas of light grain. Here are images of four sides of Stone #4:

Stone #4, Side A.
Stone #4, Side B.
Stone #4, Side C.
Stone #4, Side D.

And three sides of Stone #9:

Stone #9, Side A.
Stone #9, Side B.
Stone #9, Side C.

Stones #5 and #7 are much darker in colour, so their white veins stand out more. Stone #7 in particular has an intriguing band, maybe quartz:

Stone #5, Side A.
Stone #7, Side A.
Stone #7, Side B.
Stone #7, Side C.

Part Two on the rest of the stones can be found here.

“O” is for “Opaque Orepuki Orbicular Jasper” and “P” is for “Planet in a Pebble”

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

The following are my Posts for “O” and “P” in the alphabetical series of a Facebook Group I belong to, “New Zealand Lapidary, Rocks, Minerals, Fossils”. The first Posts in this Series can be found here.

“O” is for “Opaque Orepuki Orbicular Jasper” – This small (thumb-nail sized) tumble-polished orbicular hematite jasper was found on Gemstone Beach, just a kilometre west of the small Southland town of Orepuki.

A small orbicular hematite jasper from Gemstone Beach, Orepuki.

Jasper is an “opaque” rock. Opaqueness is one of the three main ways of classifying how light passes through a stone or rock. “Transparent” means light passes through easily (e.g., clear quartz); “translucent” means only limited light is able to pass through the stone, so that an object held behind it would look fuzzy; “opaque” means light does not pass through the stone at all. Jasper is an opaque form of chalcedony, a cryptocrystalline form of silica. Chalcedony itself is usually described as semi-transparent or translucent. The incorporation of minerals, such as iron oxides, provides jasper with its opaque nature. “Orbicular” jasper is a variety of jasper which contains orbs or spherical features. Mindat states it is “a highly silicified rhyolite or tuff that has quartz and feldspar crystallized into radial aggregates of needle-like crystals forming orbicular (spherical) structures”. If the orbs are red, we tend to call it “poppy jasper”. One type of orbicular jasper is “ocean jasper”, a trademarked name for a multi-coloured stone from Madagascar. Sometimes it can be difficult to distinguish between orbicular and some forms of brecciated jasper.

Page 72 of A.B. Busbey, R.C. Coenraads, D. Root and P. Willis, 2013, “Rocks and Fossils”.
Part of page 72 of A.B. Busbey, R.C. Coenraads, D. Root and P. Willis, 2013, “Rocks and Fossils”.
Page 122 of P. Polk (2016), “Collecting Rocks, Gems and Minerals: Identification, Values, Lapidary Uses”.
Part of page 122 of P. Polk (2016), “Collecting Rocks, Gems and Minerals: Identification, Values, Lapidary Uses”.
Www.mindat.org/min-27171.html
Ocean jasper. https://www.entertheearth.com/the-geology-varieties-and-history-of-ocean-jasper-part-one/?fbclid=IwAR3sBTOMAxOzoMR1I5G76-1Yujb0ZZqpdR4PTCsqWum0o4XGYOLtHVPOVQY
A similar small jasper stone from Gemstone Beach, could be brecciated rather than orbicular, difficult to tell clearly.

My stone was found on Gemstone Beach near Orepuki, which Wikipedia describes as “a small country township on the coast of Te Waewae Bay, some 20 minutes from Riverton, 15 minutes from Tuatapere and 50 minutes from Invercargill”. Once a thriving settlement of 3000 people, with gold mining, oil shale, and flax being big industries, today about 60 people live there, with the tavern and café being the only two town businesses (http://www.stuff.co.nz/…/orepuki-much-more-than-just-a…). The Wikipedia entry on Orepuki mentions nearby Gemstone Beach, even noting that “this wild beach contains semi-precious gemstones such as… orbicular jasper” (https://en.wikipedia.org/wiki/Orepuki). The photo below of the sweep of Te Waewae Bay, looking west past Gemstone Beach, was taken at the spot marked with a red X on the satellite map, on the eastern outskirts of Orepuki.

Gemstone Beach scene.
Looking west along the sweep of Te Waewae Bay. Photo taken from eastern outskirts of Orepuki, with Gemstone Beach being 1 to 2 kms from this point. The site from which the photo was taken is marked on the bottom left of the next photo.
Orepuki and Gemstone Beach on Google Maps http://www.google.co.nz/…/@-46.2811355…/data=!3m1!1e3. Red X at lower left marks spot from which previous photo was taken.
Page on oil shale mining at Orepuki on 19th century – page 19 of Heritage Trail booklet.
Page on Gemstone Beach area – page 25 of Heritage Trail booklet.
Booklet I bought from Riverton/Aparima Museum Shop.

“P” is for “Planet in a Pebble” – This small polished grey stone is from Gemstone Beach. Like a handful of other stones I have found, it is possible to imagine that you are looking down on a planet from space, with lots of stuff going on in the atmosphere or on the liquid surface.

“The Planet in a Pebble” is also the title of a book published in 2010 by the Polish geologist Jan Zalasiewicz, sub-titled “A Journey into Earth’s Deep History”. In this fascinating and engaging book, he tells the story of a pebble’s history, stretching back billions of years. In Chapter One, “Stardust”, he points out how, at the atomic level, a pebble and a person share the same kind of atoms – we are kin. And a pebble is a microcosm of the Universe, made up of that which goes back to the singularity of the beginning of everything. Zalasiewicz writes on page 7, “The pebble, in this respect, is as deep a mystery as is everything else in the Universe. How did the matter of that pebble, and of the…hills it was torn from, and of the world it sits atop – and of the Solar System and of the Milky Way, and of countless galaxies near and far – manage to unpack itself from a point: a ‘singularity’, as many think, of no size at all?” As I mentioned in a blog post I wrote five years ago, a pebble is made of stardust and in it we encounter not only our selves but also the depths of the Earth and the heights of the heavens. Looking down is a way of looking up. Looking into a stone is also to glance across deep dark space and even time. In a stone we make contact with that which is closest to home as well as that which is furthest away. The photos of the stone below include colourful experimental ones, playing around with Picasa software.

See here for the next Post in this Series, and here for the Series Index.

National Lockdown #2, Stone of the Week, Week Two

My small personal Facebook community voted on a Stone of the Week for Week Two. They chose Stone #14, the conglomerate from Slope Point (interestingly, Week One’s stone was also from Slope Point).

Side C.

Second place was Stone #10, the small white hydrogrossular garnet from Gemstone Beach.

This is the final Post in the National Lockdown #2 series as most of New Zealand moved out of Lockdown on 1 September. The city of Auckland continues to experience new cases of Covid-19 (down to 20 on 4 September) and will remain in Lockdown until the virus is eliminated from among the community there.

National Lockdown Number Two: Stone 14

The last Stone-of-the-Day for this National Lockdown is a small conglomerate stone from Slope Point (bottom of the South Island) that I found in June and finished tumble polishing two days ago.

Side A.

It is amazingly complex, and has polished well, apart from a couple of tiny rough patches.

Side B.
Side C.

Most of New Zealand, including my home area of Whanganui, drops to Alert Level Three tomorrow (1 September). This level continues to have a lot of restrictions, but will be reviewed in one week’s time. Auckland is still experiencing new daily cases of the Delta variant of Covid-19, though they are starting to decrease slowly, 53 yesterday and 49 today, and will remain at Alert Level Four, Lockdown, for at least another two weeks.