I arrived at Gemstone Beach at 9.20 am today, a sunny warm morning, seeking more stones for tumble polishing. There was only one other vehicle in the carpark – its occupants were on the beach but about to leave, one of them carrying what looked like a heavy bucket. We got talking, and they turned out to be Helene and Steve from Auckland, Helene being a member of the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils”. They were really enjoying exploring the stones on Gemstone Beach. One change on the beach in front of the carpark was the presence of a dozen or so large cobbles (see photo below). These have not been there over the past three months. I don’t know whether the sea had brought them in or whether sand had been removed to uncover them.
I walked to the Waimeamea River again, much of the beach west of the Taunoa Stream being in the shade of the cliffs at this time of the morning. I worked hard at being selective in what I collected – I have just packed up some stones to courier home to Whanganui and there’s still plenty to pack into my car when I leave Southland at the end of this month. I was only partly successful in restraining my collecting as I keep finding amazing little stones. I ended up with maybe one-third of what I have usually collected recently. The tide was coming in, so I didn’t stick around too long, eventually leaving the beach two hours after I arrived.
Ten stones are featured in this Post, nine that I collected and one that I left on the beach. Today’s MVP (Most Valued Pebble) is a small stone with bright white patches and very fine lacy brown veins of mineral.
What tumbling will do to the fine lines in this stone I don’t know – I will likely begin it in a fine grit.
The next stone, only 3.5 cm long, is a breccia with tiny fragments, even with some sorting by size especially on the second side shown below:
The first of the next two stones is maybe amygdaloidal – a volcanic stone with infilled holes – while the second is probably rhyolite.
Two different kinds of breccia, stones composed of small sharp fragments cemented together in a fine-grained matrix:
This beach contains quite a few green quartzite stones and lots of small dark-red coloured stones, some of which are jasper, some being volcanic stones:
A stone that I found on the beach but was too big for tumble polishing was worth recording because of the trace fossils in it as well as a light-coloured vein with brecciations:
Post 49 is entitled “Photographing What’s There” at Gemstone Beach. The first Post in the “Southern Sojourn 2023” Series is here. The Index to the Series is here.
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