I arrived in Kakanui, North Otago, just after noon today and immediately visited Seadown Beach for a 90 minute fossick at low tide, looking for stones to tumble polish. The sun was shining but it was only 11 degrees and a coolish wind was blowing. I spent the time at the south end of the beach where there were plenty of stones. I ended up putting about 65 stones in my bag. Ten of them are featured in this Post.
I kept my eye open for the usual kinds of stones I find here – especially jaspers, quartzites, and fossilised seafloor stones – and I found a few. I looked carefully for fossil bryozoan stones but came up empty this time. I did come across an intriguing stone, today’s best find, an amazing complex and colourful stone:
The stone is 5.5cm long. I posted some photos of it in the Facebook Group “New Zealand Lapidary, Rocks, Minerals, Fossils”, seeking an identification. The answer offered was a piece of fossilised bone, which I had kind of suspected but was unsure as I have not personally come across such a beauty before. It was also suggested that it is an agatised fossil. Thanks to the Group for this information.
Another colourful find is this smaller green quartzite stone, 4 cm long and much thinner than the previous stone. Its deep green and contrasting white caught my eye immediately.
The best of my jasper finds today – a small smooth dark red pebble:
Another of my smaller finds was this one – such an interesting vein running along the lower part of it:
Two of the yellow quartzites I collected – I am always attracted by the clouds of mineral colour in them:
A red version of this kind of quartzite:
For information on the range of colours of these quartzites, see the entry for Wednesday 26 May 2021 in this Post.
This little stone also caught my eye, with its seemingly fragmented sections:
The next, and nineth, stone is the most interesting of the handful of “fossilised seafloor” stones I collected today:
These stones are softer than the previous ones and need to be treated lightly when tumbling (like the limestone pebbles from Ward Beach). See this Post for more about tumbling this type of stone.
Finally, a stone that won’t tumble at all – it will likely crumble quickly in the barrel. But it is Kakanui Mineral Breccia, a distinctive local rock type that has attracted some international interest geologically:
Kakanui Mineral Breccia is a mineral-rich fragmental rock which formed from the contact of an intruding magma with water about 32 million years ago. The violent eruption totally disrupted the magma components into angular fragments. The site of the eruption was just offshore from Kakanui village. For more, see the section on Kakanui Mineral Breccia about halfway through this Post, where Kakanui Beach is discussed.
The first Post in this Series is on a fossick at Ward Beach. The next Post is about another Kakanui fossick.
Loving that jasper and that oblong green one of course!! One day I hope to meet you in Kakanui and have a fossick at Seadown together!