“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.

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