Log of TZC2393 on completion of cutting
Cut Shape : Pear

Video Log of TZC2393 on completion of cutting

Log of TZC2393 in its rough state

ID # TZC2393

Geological History

The Merelani Mining area beneath Mount Kilimanjaro is the only known source of Tanzanite in the world. This makes the stone considerably rarer than Diamonds and one with a finite resource.

This gorgeous Tanzanite is one of a very few produced in a very small window of the earth's history. It was formed 500 million years ago. The host rock it formed in are late Proterozoic metasediments that were originally a series of sands and clays rich in organic matter with elevated levels of uranium, vanadium and aluminium rich minerals. These sediments were highly weathered and deposited in a lake. During and after the Pan-African tectono-thermal (mountain building) metamorphism a release and migration of hydrothermal fluids took place. The result was the deposition from these fluids of calcium, magnesium, vanadium, uranium, strontium and Zinc as well as heavy rare earth elements Co2 and SO3 along the Lelatema fault zone into chocolate tablet shaped boudin structures.

This rare Tanzanite was amongst a number of crystals that formed in this structure as a result of the enormous geological events that formed the mighty Mount Kilimanjaro. It lay there for hundreds of millions of years until it was discovered by independent Tanzanite miners as they explored deep into the earth's surface. The rough crystal found its way to Lapigems Gem Company's offices nearby in Nairobi where it was cut and heated.

All Tanzanite is heated at 600 degrees centigrade as much of the time, rough crystals are a red-brown color and the heating removes this element and leaves the blue and violet axis as dominant. Heating is a stable and permanent treatment. Five hundred million years after its conception this lovely, rare crystal finds itself in human hands.