The second revised edition of the photobook “The Trace Fossils of Gemstone Beach” includes a page of photos of stones that I have collected from a stretch of beach just south of Timaru in South Canterbury. I access what I call Timaru South via Scarborough Road, parking where that road meets The Parade. There is a walkway nearby that crosses the railway line and dips down near the beach. I view Timaru South as a stretch of stony beach that starts near Redruth Park, just under one kilometre south of Patiti Point in Timaru, and runs southwards a further four and a half kilometres or so, past the Jack’s Point lighthouse to the Ellis Road Beach carpark. Some of the stones I find here can also be found further north at Birdlings Flat and further south at Kakanui. It is one of the beaches that I visit only occasionally, on my way north or south.
The stone numbers on the scan of page 27 below don’t appear in the book but have been added so I can refer to each of them:
#1 – Probably an igneous stone, a pale green porphyry with feldspar crystals (see after Stone #4 below for a close-up). A porphyry has well-formed crystals visible to the naked eye (called “phenocrysts”), set in a fine grained matrix. Porphyries usually develop when magma that has been slowly cooling and crystallising within the Earth’s crust suddenly erupts at the surface, causing the remaining uncrystallised magma to cool rapidly (see “Textures of Igneous Rocks” in University of Auckland Geology). This means a porphyry is intermediate between quickly solidifying fine-grained igneous rocks and the slowly solidifying igneous rocks with uniform larger crystals. I found this one in March 2026 but have come across similar ones at other times.
#2 – I refer to this stone as a dark quartzite and have found a handful of these here. I picked this one up in February 2025.
#3 – Found on the same day as I found Stone #2, this might be a brecciated jasper (breccia meaning consisting of sharp-edged fragments). It is a much lighter colour than many, with Stone #5 below an example of a darker one. Alternatively, the fine grain of its composition hints at maybe it could be a brecciated mudstone instead.
#4 – One of the many green quartzites I have found on this beach (close-up below, right). I picked this one up in July 2026, the day I found a number of others on this page (#6 and #7). A very good example of this type of green quartzite is featured in “T is for Timaru Today”. See this Post for a variety of other specimens.
#5 – This stone is a dark red brecciated jasper that I collected in March 2026. Jaspers can often be found here. A Timaru South hematite jasper is the third entry in TumbleStone’s Hall of Fame.
#6 – I found this stone the same day that I picked up Stone #4 above, in July 2026. In the Post for that day, I described it as “a pale quartzite with thin green and red threads”.
#7 – Again a quartzite, this one mainly yellow/orange with a touch of brown, again found in July 2026.
#8 – Maybe a quartzite, not sure, found on Timaru South in February 2025, the same day as Stones #2 and #3. After Stone #11 below is a close-up.
#9 – Probably another porphyry, like Stone #1.
#10 – Another green quartzite. Found in January 2023.
#11 – A jasper with a lot of fine detail in it, again found in July 2026.
I will produce Posts on the stones on other pages of this book over the next few days.
