Jasper pigment

Last year, when Maggie, Reiner and I were looking for magnetite along the shores of Lake Huron, we found a couple of nice samples of red jasper pebbles.

At the time Reiner wondered aloud whether they could be used to make pigment colour, but with the rush of the project at full throttle, I really didn’t give it a second thought.  But today I was cleaning up one of the bowls of pretty rocks I have on my desk when I came across a few samples of the jasper we had found.  I think it’s time to find out what is possible!

Jasper is basically chert, which owes its red color to iron(III).  It is an amorphous quartz and in small occurrences, it is fairly common.  Without looking specifically for it, we had collected half a dozen samples.

With my son helping, we decided to pulverize two of the rocks.  In picking them they looked very similar, and I expected to just mix the resulting powder together when we where finished.  But, to my surprise, once we had crushed them they produced two very different colours: the first was a bright, opaque red; the second a transparent pink.  These distinct colours continued to develop as we refined them.  And, as you can see from the photograph above, the final colours were noticeably different.

The pigment was very sandy and hard from the collected samples, but with a little extra work, they ground up into a usable pigment.  The first sample produced a red that I would love to add to my palette, but whether or not there are enough pebbles to match its intensity remains to be seen.

I have no worries about this pigment being light-fast, and when I need a slightly transparent colour in my work, this pigment would be very suitable.

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