Is Kambaba Jasper a Fossil? What Kambaba Stone Really Is

Kambaba jasper, the dark green Madagascar stone with black orbs and rings, is sold almost everywhere as a fossil stromatolite: the petrified remains of ancient cyanobacteria, billions of years old, the organisms that gave Earth its oxygen. It is a wonderful story, and we told it ourselves for years. It is also wrong. Laboratory analysis shows kambaba jasper is a volcanic rock, not a fossil. Here is what it really is, where the stromatolite story came from, and the real stromatolites that deserve the credit.

What Kambaba Jasper Really Is

Kambaba jasper is an orbicular rhyolite from the Bongolava region of west-central Madagascar. Rhyolite is a volcanic rock, the fine-grained equivalent of granite, and "orbicular" describes the round structures that give kambaba its crocodile-skin pattern. The green groundmass is a fine mix of quartz, feldspar and aegirine, a dark green pyroxene. The black orbs are lithophysae, rounded growths that formed as gas-rich lava cooled, and they are packed with tiny needle-like crystals of amphibole.

Those amphibole needles are the giveaway. Amphiboles crystallize from cooling magma; they do not form in the limestone mud of a lagoon. When EPI, Germany's gemstone testing institute, examined kambaba jasper by thin section and X-ray diffraction, the verdict was an igneous rock of volcanic origin. Stromatolite specialists who have looked at it under magnification agree that the structures do not resemble stromatolites, and the reference book Stromatolites (Leis and Stinchcomb, 2015) describes the material as lithophysae that are "almost certainly not biogenic in origin."

Kambaba is a close relative of ocean jasper, which comes from the same island and formed the same way in brighter colors. Neither is a true jasper, which is a form of quartz; "jasper" here is a trade name for an opaque stone that takes a good polish. Kambaba is hard, about 6.5 to 7 on the Mohs scale, and is normally sold untreated.

Where the Stromatolite Story Came From

Kambaba does look the part. Its dark green color and concentric rings resemble the layered mounds that microbial mats build, and the name "green stromatolite jasper" attached itself early and spread from one seller's listing to the next. Add the appeal of wearing a 3-billion-year-old fossil, and the story was never going to go away on its own. But the color of a fossil tells you nothing about the color of the organism, the rings in kambaba are far too regular and too round for microbial layering, and the mineralogy settles it.

The Real Stromatolites, and Why They Matter

For most of Earth's early history the atmosphere was nitrogen, carbon dioxide and water vapor, with almost no free oxygen. Around 3.5 billion years ago, mats of microbes in shallow lagoons began trapping sediment and cementing it, layer upon layer, into mounds of limestone called stromatolites. Among those microbes were cyanobacteria, the first organisms to carry out oxygenic photosynthesis: using sunlight to turn carbon dioxide and water into sugar, and releasing oxygen as the by-product. Over hundreds of millions of years that oxygen built up in the oceans and then the air, transforming the planet in what geologists call the Great Oxidation Event and making complex life possible. Stromatolites are among the oldest fossils known, and the ones in the Pilbara of Western Australia are about 3.5 billion years old.

Living stromatolites still grow today in Western Australia, in the photo above, most famously at Shark Bay, and in the Bahamas, in water too salty or too harsh for the grazing animals that would otherwise eat the mats.

How to Tell Fossil Stromatolite From Kambaba Jasper

Genuine fossil stromatolite is also cut into beads and cabochons, and it is worth owning for exactly the reasons the kambaba legend claims. Telling them apart is easy once you know what to look for:

• Pattern. Stromatolite shows fine, wavy, slightly irregular layers, often domed, like the growth rings of a tree that has been squashed. Kambaba shows round orbs with dark centers and rims.
• Color. Fossil stromatolite is usually grey, tan, cream, rust or brown, the colors of limestone and iron staining. Bright or dark green points to kambaba.
• Hardness and feel. Stromatolite is limestone-based and softer, around 3 to 4 on the Mohs scale; kambaba is 6.5 to 7 and takes a glassier polish.
• Source. Fossil stromatolite for jewelry comes mostly from Bolivia, Morocco, Australia and the American West. Kambaba comes from Madagascar.

Does It Change How You Use the Stone?

Not really. Kambaba jasper is still a beautiful, durable natural stone with one of the most striking patterns in the bead world, and the crystal traditions that call it a stone of tranquility never depended on its age. You will find its traditional meaning and stone pairings on our kambaba jasper beads page. It just isn't a fossil, and we would rather sell it as what it is.

Frequently Asked Questions

Is kambaba jasper a real jasper?

No. Jasper is quartz; kambaba is an orbicular rhyolite, a volcanic rock. The name is a trade name, as it is for ocean jasper and several other Madagascar stones.

How old is kambaba jasper?

Nobody has published a reliable date for the Bongolava rhyolites, but the "3 billion years" figure in most listings comes from the stromatolite story, not from the rock. It is a volcanic rock of ordinary geological age, not a relic of Earth's first life.

Where does kambaba jasper come from?

Madagascar, from the Bongolava region in the west-central part of the island. Some material is attributed to South Africa, but Madagascar supplies nearly all of the beads on the market.

Can I buy real fossil stromatolite beads?

Yes. They are sold as stromatolite, usually in grey, tan and rust tones with wavy layering. If a listing calls a green orb-patterned stone "stromatolite," it is kambaba.

Shop Kambaba Jasper Beads

Our kambaba jasper beads come in a range of shapes and finishes. If you enjoyed this, you may also like Real Malachite vs Fake Malachite and What is White Turquoise? It's Just Howlite.