June-July 2026 South Island Trip – Part 4, Intriguing Details in Small Jaspers Found on Gemstone Beach, Wednesday 1 July

I returned to Gemstone Beach, by myself, two days after my first visit. It was just after high tide when I arrived at 1.50pm. The weather was good again, being sunny and 12 degrees with only a very light breeze. I spent two hours there, walking down to the Waimeamea River and back. Today the Waimeamea was cut off from the sea by stones brought in by the waves over the last couple of days.

The Stream With No Name, near the carpark.

Stones in the Stream With No Name.

Looking down on the Taunoa Stream from a nearby hill.

The Waimeamea River, cut off from flowing to the sea.

This afternoon’s 29 finds.

Among my 29 finds today were eight small dark red jaspers. It turned out that they were a lot more interesting than I initially thought. Close-up photos revealed all sorts of surprises, from spherulites(?) and epidote patches to agate and quartz-filled veins:      

Spherulites? See next photo.

Outline of possible spherulites.

Tiny waterline agate in vein.

Intriguing quartz vein.

Dark hematite and white quartz.

Dark hematite and translucent quartz.

Patches and patterns.

Some green epidote in the mix?

Varying size of veins.

Tiny dark orbs?

Spherulites are balls of radiating needle-like crystals, and the radiating lines in the first small jasper above are very reminiscent of a certain type of spherulite. I’ve seen spherulites in rare specimens of rhyolite from Gemstone Beach and Slope Point though they have often had a tighter pattern than apparent in this small jasper. However, maybe these lines have been formed from a different process, I’m not sure.

I picked up two unusual trace fossil argillite stones. The first has raised traces, with one particularly long and sinuous one:

Trace fossils in argillite.

The second is opposite in character. Its traces are much more subtle and appear wispy, almost fern-like: 

Trace fossils in argillite.

This small green quartzite is of a type that can be found from time to time on Gemstone Beach, deeply colour by epidote – I love the details of fragmentation and veins:

Small green quartzite.

Other side of small green quartzite.

An Index to this Series of Posts is available here. The next Post describes a visit to Papatotara Beach (not yet available). 

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