Jasper is an opaque, microcrystalline variety of quartz—specifically, chalcedony—that’s often richly colored due to the presence of various mineral impurities. It comes in virtually every color, but red, brown, yellow, and green are the most common. Some varieties, like picture jasper, feature striking banded, orbicular, or scenic patterns.
Jasper forms when silica-rich
solutions—often from volcanic ash or sediment—seep into cracks and pockets in
the Earth’s crust. These solutions carry along a whole cocktail of minerals
that contribute to the wild variety of hues and markings. Over thousands, even
millions, of years, these silica solutions harden into microcrystalline
quartz—layer by layer, pattern by pattern. The result is jasper: stone born
from slow-moving water and fire.
And it’s everywhere. Jasper is not
rare—it can be found on nearly every continent. From the windswept coasts of
Madagascar to the convulsing mountains of Montana, it shows up in all its
regional variations. In addition to being blessed with striking colors, jasper
takes and holds a polish remarkably well.
Yesterday, on my annual visit to the
Helena Mineral Society’s Gem, Mineral, and Fossil Show, I felt compelled to buy
four specimens of jasper. Two are from Madagascar, one was fished from
Montana’s Blackfoot River, and one is of unknown origin. No matter. All are
lovely. I am sharing a photo of the stones here today.
—Mitchell Hegman
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