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.
Kambaba Tumbling Rough
, , and What do they mean?
Size: mostly 1/2 to 2 inch pieces
A few pieces of Kambaba that we tumbled. We really like the green and black eyes and swirl patterns in the tumbled stones.
What is Kambaba?
Kambaba (also known as "Kambamba" and "Crocodile Jasper") is a green tumbling rough marked with black that is mined in Madagascar (a large island in the Indian Ocean, off the southeast coast of Africa). It produces dark green tumbled stones with spectacular black "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 background color 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.
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.
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