Kambaba Rock Tumbler Rough

Also Known as "Kambamba" and "Crocodile Jasper"

This image shows some Kambaba tumbling rough, dumped into a colander and sprayed with water to reveal its full color. The pieces in the photo are between 1/2 and 2 inches across their maximum dimension. Click on the image for a larger view.

Here are some of the nice tumbled stones that were produced from the rough rock. Tumbled stones by Adam Rittenhouse, photograph by Angela King.

Kambaba Tumbling Rough

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Size: mostly 1/2 to 2 inch pieces

What is Kambaba?

Kambaba (also known as "Kambamba" and "Crocodile Jasper") is a green and black tumbling rough that is mined in Madagascar (a large island in the Indian Ocean, off the southeast coast of Africa). It produces tumbled stones with spectacular "eyes" and "orbs". The name "Crocodile Jasper" began when some people thought that the orbs looked like crocodile eyes!

All over the internet, people have been calling this material Kambaba "jasper", "nebula stone", and "fossilized stromatolite" (sedimentary trace-fossils built by sediment-trapping algae). It has been a real mystery rock.

However, the Institut für Edelsteinprüfung made thin sections and went to their microscopes. They discovered that Kambaba is an igneous rock, crystallized from a viscous magma, that is composed mainly of quartz and alkali feldspars. It also contains green amphibole crystal clusters with a radial habit and fine-grained pyroxene.

There you have it... this rock is not a jasper, not a stromatolite, and not a "nebula stone". Instead, it is a rhyolite - an igneous rock. We had some thin sections made and saw many of the features reported by the Institut für Edelsteinprüfung. Thank you to them for their enlightening work.

What Is Being Sold Here?

These pieces of Kambaba are large enough (mostly 1/2 to 2 inches across in the rough) to make tumbled stones that beautifully display Kambaba's green and black orbicular markings.

The rock is slightly softer than many agates and jaspers (about 6 to 6 1/2 on the Mohs scale), which enables it to shape quickly and nicely in a rotary or vibratory tumbler. This rock has very few pore spaces - and that allows it to be polished to a high luster with TXP aluminum oxide polish.

Rotary tumbler recipe for jasper and agate

Yes, this is not a jasper - but it tumbles like one: So, we recommend our rock tumbling instructions for jasper and agate. That recipe is summarized in the table above, but we suggest that you see the full instructions for rotary and vibratory tumbling.

EASY Rock Tumbling Recipe:

Kambaba (1/2 to 2 inches)

When we tumble Kambaba, we use our rock tumbling instructions for jasper and agate. It is not a jasper and not an agate, but it behaves like them in rotary and vibratory tumblers.

In rotary, we usually run it for two weeks in coarse grit, one week in medium, one week in fine, one week (or a little longer) in polish, then give it 60 minutes of Ivory Soap burnishing.

Tumbled Stones Often Available

If you would rather just purchase tumbled stones of this material, we usually have medium-size tumbled Kambaba here.

Large Ceramic Media

Large ceramic pellets work great as a filler and for delivering grit or polish to difficult-to-reach surfaces. More information...

Small Ceramic Media

Small ceramic pellets work great when you need small material for better tumbling action or to deliver grit or polish to difficult-to-reach surfaces. More information...

Standard Grit Kit

1 pound of each: coarse, medium and fine grit. 8 ounces of TXP polish. This is enough supplies to tumble up to four three-pound barrels of rocks. Save money with a large grit kit.