Zebra Rock and Primordial Stone Testing
Here are two interesting stones from Kununurra in the East Kimberley of Western Australia. The first stone is known as ‘Zebra Rock’, and the second piece that looks a bit like a Belgian Coticule, is referred to as ‘Primordial Stone’.
According to the info card, and the quarry’s website, both are siltstone, and the Primordial is loaded with fossilized algae.
The Zebra rock bad been damaged in transit to the original owner, who kindly sent these samples for me to ‘test’.
My first impression of the Zebra Rock is that it’s extremely porous, and that would complicate using it as a razor hone. It feels very dry in the hand, and when you spray it with water, it soaks every bit in almost immediately. My instincts tell me that soaking this stone to full saturation might not be a good idea, the ‘feel’ in my hands suggests that doing so might cause the stone to turn to mush. I could be wrong – but I don’t want to risk ruining the sample.
Zebra rock test, using water as a honing medium.
The Zebra Stone did not impress me. Honing on it didn’t bring any great feelings and the scratch marks on the bevel suggest that, if anything, it’s a mid range option. The scratches were fairly uniform, but I did not get any sense of it removing material – almost like it’s scratching and polishing but not cutting to any great degree.
The Primordial is different – This stone ‘feels’ more like a whetstone should feel.
It too feels a bit ‘dry’ - but a spritz of water will stay put on the working surface of either side for a decent amount of time. The white portion seems/feels more coarse, and seems ‘drier’. The red portion feels finer.
Primordial test, using water as a honing medium.
The Primordial did ok here. The white side ponied up a decent mid-range effort; lets say 6k-ish. The Red side was markedly finer and perhaps a bit slower, lets say pushing up to 8k with a very consistent scratch pattern and a nice polish.