January 2023 – TumbleStone

Online Access to “Gemstones” by Jocelyn Thornton (1985)

Front cover of booklet.

Pages 18 & 19 of Jocelyn Thorton’s “Gemstones” (1985)

Pages 64 & 65 of Jocelyn Thorton’s “Gemstones” (1985)

Pages 68 & 69 of Jocelyn Thorton’s “Gemstones” (1985)

This valuable booklet, now hard to find in secondhand bookstores, used to be available online on Peter Thornton’s website [www.peterthornton.com/files/nzgemstones.pdf]. I briefly reviewed it in TumbleStone Blog back in 2016 (see here) and have often referred to it, for example, in Posts on Gemstone Beach and Slope Point. However, I noticed a few weeks ago that it was no longer available. I have managed to find two alternative ways to access it online.

The first (and probably the best) is via an information site on Tuatapere, a town not far from Gemstone Beach. The site is called “On Natures Edge – Tuatapere” and its “What’s Here” section has a brief page on Gemstone Beach www.onnaturesedge.co.nz/tuatapere/whats-here/gemstone-beach. This page has a link to Thornton’s booklet (see below). Clicking on the link brings up a pdf file of the booklet, the same file as used to be available on Peter Thornton’s website. By clicking here, you can go directly to the pdf.

Part of “Gemstone Beach” page in “On Nature’s Edge” https://www.onnaturesedge.co.nz/tuatapere/whats-here/gemstone-beach/

Pdf file from “On Nature’s Edge” https://www.onnaturesedge.co.nz/downloads/nzgemstones.pdf

Part of pdf file from “On Nature’s Edge” https://www.onnaturesedge.co.nz/downloads/nzgemstones.pdf

The second alternative source is through StudyLib.net (see below) – click here. It can take a little time to load, and initially the pages look small, but it appears to be a good reproduction. You can scroll down through the pages within the file, and can zoom in to a size that suits you. The links in the Contents page are shortcuts to other pages, as in the pdf file in “On Nature’s Edge”.

Thornton’s “Gemstones” on StudyLib.net https://studylib.net/doc/8213257/gemstones–new-zealand-nature-series-

StudyLib.net often includes ads

Contents page at 31.33% siize

Contents page zoomed into 80%

Note that the booklet itself contains 74 pages, each side of each sheet being numbered. The pdf files, however, counts two facing pages as only one page, reducing the page numbers by half.

Slope Point Diversity, 25 Recently Polished Slope Point Stones: Part Three – Stones 17 to 25

This Series of Posts features Slope Point stones from a recently completed 3lb barrel. The first Post featuring Stones 1 to 8 can be found here. The order of presentation of stones is random. Many of them are likely to be rhyolite but I am unsure about the identification of some of them.

Stone 17 is a purple rhyolite, 4.5 cm long:

Stone 17, rhyolite.

Other side of Stone 17.

Stone 18 is a brown rhyolite, 3.5 cm long:

Stone 18, rhyolite.

Other side of Stone 18.

Stone 19 is a black rhyolite, somewhat similar to Stones 7 and 14 (see previous Posts):

Stone 19, rhyolite.

Another side of Stone 19.

Another side of Stone 19.

Stone 20 is a white and caramel stone, I am unsure of its identification – other light-coloured stones include Stones 7 and 15:

Stone 20.

Other side of Stone 20.

Stone 21 is very different in colour – green – from the other stones in this Series. I suspect it has volcanic origins but am unsure of its identification.

Stone 21.

Other side of Stone 21.

Stones 22 , 23, 24 and 25 are the smallest stones in the batch. Stones 22 and 23 are each 2.5 cm long while Stones 24 and 25 are only 2 cm long each. Stone 22 might be rhyolite:

Stone 22, probably rhyolite??.

Other size of Stone 22.

Most of the surface of Stone 23 failed to polish but there are some fascinating patterns in it:

Stone 23.

Another side of Stone 23.

Another side of Stone 23.

Stones 24 and 25 are both rhyolite, in my view, with Stone 25 especially showing some nice flow banding:

Stone 24.

Other side of Stone 24.

Stone 25, small flow banded rhyolite.

Other side of Stone 25.

I continue to be fascinated by the diversity of Slope Point stones which are quite different from the stones I find at the likes of Gemstone Beach and Kakanui.

Slope Point Diversity, 25 Recently Polished Slope Point Stones: Part Two – Stones 9 to 16

This Series of Posts features Slope Point stones from a recently completed 3lb barrel. The batch had tumbled in a fresh lot of tin oxide polish for 12 days then was burnished in borax for eight days. Part One featured Stones 1 to 8 and Part Three will feature Stones 17 to 25. The order of presentation of stones is random. Many of them are likely to be rhyolite but I am unsure about the identification of some of them.

We start off with three stones with white “spots”. Stones 9, 10 and 11 are what Jocelyn Thornton in “Gemstones” (page 35) calls “flower garden” rhyolites, “the local name for rhyolites with white and grey circles and centres”. These three stones are between 3.5 and 4 cms long.

Stone 9, flower garden rhyolite.

Other side of Stone 9.

Stone 10, flower garden rhyolite.

Other side of Stone 10.

Stone 11, flower garden rhyolite.

Other side of Stone 11.

Stone 12 is quite different. It might be petrified wood, with a vein of some kind of chalcedony, maybe agate, or it might be quartz in the vein. The stone is about 3 cms long.

Stone 12, petrified wood?

Another side of Stone 12.

A third side of Stone 12.

Stone 13 is a volcanic stone, a bit smaller, 2.5 cms wide. One side is dominated by white opaque crystals.

Stone 13.

Other side of Stone 13.

The final three stones in this Post are all rhyolites but of different colours. Stone 14 is a dark gray, Stone 15 is lighter in colour and with some orange-brown staining, and Stone 16 has some patches of dark purple amidst the white: