The GemHunter

Professor Hausel's Guide to Finding Gemstones, Diamonds, GoldRocks & Minerals 

Unusual Rocks

“I'm allergic to rocks hitting me in the face.”
Mike Rowe

Without rocks, the earth would be boring. Could you imagine living on a gas giant like Jupiter - ugh! Where are the rocks? As geologists and rock hounds - we love rocks. Rocks have their own beauty and are formed of many individual crystals.

One of many unusual rock types known as spinifex-textured komatiiteThe photo to the left is from the Hannas Lake Serpentinites in Western Australia. This is an ultramafic spinifex komatiite. If you find any rocks like this one, you may be near a gold, nickel or chromite. These rocks are typically found in greenstone belts around the world. 

Another uncommon rock is kimberlite. Kimberlite was named after the Kimberley Region of South Africa. It has also been found in North America in Canada, Colorado, Wyoming, Montana, Michigan, New York, Kansas, Kentucky and Tennessee. Then there are lamproites. The leucite hills near Rock Springs has several volcanic flows, breccias and necks of lamproite. Similar rocks are found in Kansas and Montana. And the more olivine-rich lamproites are the best lamproitic rocks for diamonds.