14" Marra Mamba Tigers Eye Section -Mt. Brockman (2.7 Billion Years)

This is a gorgeous, 14" polished section of 2.7 billion year old Marra Mamba Tigers Eye From Mt. Brockman in Western Australia. One side has been cut flat and polished to a mirror-like finish. The opposite side has been left rough.

One edge has been cut flat, allowing for aesthetic presentation of the specimen without the need of a display stand.

Marra Mamba Tiger's Eye is a rare type of Tiger Eye found only in the Hamersley Ranges of
Western Australia. Only two deposits have ever produced “true” Marra Mamba, a rare type with reds, blues, yellow, gold and greens.

Marra Mamba Tiger's Eye formed around 2.7 billion years ago when stromatolites and other photosynthetic bacteria 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, which are now referred to as banded iron formations.

Geological movement over millions of years caused folding and faulting to occur, distortion the layers. Heated fluids passed through the rock and dissolved material and redeposited it elsewhere. The fibrous Riebeckite crystals were replaced by silica with fine dusts of yellow Goethite. These fibrous bands lead Tiger Eye to be classified as a chatoyant gemstone.

Causes of Color Banding:

  • White - Quartz

  • Yellow - Goethite

  • Red - Hematite

  • Blue - Riebeckite

  • Green - A mixture of blue Riebeckite and yellow goethite

  • Black -Hematite and Magnetite
    Marra Mamba
    Mt. Brockman, Western Australia
    14 x 5.3", up to 2.7" thick