Second Edition of “The Trace Fossil Stones of Gemstone Beach” – Page 23, “More Stones Collected from Gemstone Beach”

Book cover. A4 landscape.

Page 2, Introduction.

Page 23, the second of the two pages on other Gemstone Beach stones.

Pink thulite. Stone #10.

The second revised edition of the photobook “The Trace Fossils of Gemstone Beach” includes two pages of photos of other stones that I have collected from Gemstone Beach. Page 22 is the first of these two pages, with Page 23 (below) being the second – note that the stone numbers don’t appear in the book:   

#1 – A banded argillite, found in August 2025. Argillite is a hardened mudstone, consisting of much smaller grains than greywacke sandstone and feeling much smoother. The bands are layers of different coloured sediments. This type seems to have been subject to a bit more heat and pressure than many banded argillites, with its surface reminding me of pottery glaze. 

#2 – This stone is rhyolite, found in March 2025. I used it in a post in an alphabetical series in the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils” in January 2026. That post has some information about rhyolite and its different expressions.

#3 – This one is not easy to identify. At one point I though it might be a breccia, made up of a number of fragments, some of them a nich green hue. Then I wondered if in fact those fragments might instead be epidote crystals, which might make the stone a form of epidosite:

#3

#3

I found it on Gemstone Beach in August 2025.

#4 – Another mystery stone, one with a faint green hue, found in March 2025. It has really interesting shapes within it, as if bits of quartz have been surrounded by tiny fuzzy crystals of some kind:  

#4

#4

#5 – Collected in August 2025, this stone is a breccia, made up of small angular fragments in a fine-grained matrix . There’s some light brown colour in the stone, along with some purple threads.

#6 = A hydrogrossular garnet, found on the same day in August 2025 as I found Stone #1. 

#7 – A poppy jasper, found early on in my August 2025 trip, the day a small aircraft landed on the beach a little east of the car park.

#8 – Another find from August 2025, this black stone with white crystals is igneous, maybe dolerite.

#9 – This stone is a breccia, a mudstone that has been fragmented by tectonic pressure (also from August 2025).

#10 – A pink thulite, found the same day as Stone #7 above. 

#11 – When I found this stone on 12 August 2025, I thought it could be a hydrogrossular garnet – it had a slightly waxy feel. However, the patterns in it are not usually associated with a hydrogrossular garnet. It remains a bit of a mystery.

The next Post in this Series looks at the stones on Page 24, from Ward Beach.   

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