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.

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.

Author: tumblestoneblog

Retired Academic, male, living in the New Zealand countryside near Whanganui with his wife as well as Jasper the dog, Fluffy the cat, Dancer and Penny, the horses, and a shed half-full of stones. Email john.tumblestone@gmail.com. View all posts by tumblestoneblog