Is Kambaba Jasper A Stromatolite?

Kambaba jasper is unique, green rhyolitic (volcanic) stone found in the west-central Bongolava region of Madagascar. It is full blackish, irregularly shaped orbs that cause it to closely resemble some types of stromatolite fossils. Stromatolites are microbial reefs created by cyanobacteria (also known as blue-green algae) and their fossils are the oldest traces of life on Earth.

Based on appearance, many people have claimed that Kambaba Jasper is a fossil stromatolite, and this inaccuracy has been repeated over and over until it has simply been assumed to be correct. This has led to many people selling Kambaba jasper to make wildly inaccurate and speculative claims about the stone. This includes claiming it is billions of years old and the green coloration is due to the color of the fossilized algae. Nevermind the color of a fossil has nothing to do with the original color of the organism.

Left: Stromatolites (Hoyt Limestone, Upper Cambrian, New York, USA)  Right: Polished kambaba jasper
Left: Stromatolites (Hoyt Limestone, Upper Cambrian, New York, USA) Right: Polished kambaba jasper


Thin-film and X-ray diffraction analysis done EPI (Germany’s gemstone testing institute) shows the Kambaba jasper is a rhyolite of volcanic origin and thus can not be a stromatolite. According to the analysis it is composed of a “green ground mass of quartz, pyroxene (Aegirine), as well as soda and potash spats, circular aggregates are arranged from very small amphibole needles” Amphibole minerals form in igneous (volcanic) rocks, not sedimentary ones where fossils are found.

I’ve also asked several stromatolite experts about Kambaba jasper, and even without the chemical analysis they are pretty adamant that under magnification the structures do not look like what you would expect in a stromatolite. So, Kambaba jasper is NOT a stromatolite even if it’s superficially looks like one.

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