Saturday, 28 April 2018

Marra Mamba Tiger's Eye

Mara Mamba Tiger Eye is a rare variety of Tiger Eye found only in the Hamersley Ranges of the Pilbara region in Western Australia. Only two deposits have ever produced “true” Mara Mamba, a rare type with reds, blues, yellow, gold and greens. In 2005, David Vaughan discovered one of the largest tiger eye specimens ever at Marra Mamba.
Mara Mamba is extremely old, forming when the Earth was very young and had little to no oxygen in its atmosphere. Oxygen producing photosynthetic bacteria evolved more than 2.7 billion years ago, and gave off oxygen as a waste product. This oxygen built up in the atmosphere and dissolved in the sea water. When iron, produced mainly from huge submarine volcanoes came in contact with this oxygen, it precipitated as iron oxide in the sea floor and resulted in iron-rich and silica-rich bands, called banded iron formations (BIFs).
Gems are usually given a cabochon cut to best display their chatoyance. (cat's eye effect)