Brockman Tiger eye mine (Marra Mamba), Mount Brockman, Ashburton Shire, Western Australia, Australia
|Latitude & Longitude (WGS84):||22° 18' 0'' South , 117° 17' 60'' East|
|Latitude & Longitude (decimal):||-22.30000,117.30000|
|Köppen climate type:||BWh : Hot deserts climate|
Located approximately 50 kilometres north-west of Tom Price, near Mt Brockman, adjacent to Caves Creek Valley on Hammersley Station.
A number of deposits for Tiger Eye are found here mined by Western Australian specimen dealers, and the material is well known overseas. Probably most of the specimens sold internationally of tiger eye come from here. (Specimens labelled Perenjori are more likely to have come from Marra Mamba). Specimens may also be labelled Mount Brockman or Brockman.
The Marra Mamba Formation is an iron-rich geological unit in the Archaean-Palaeoproterozoic Hamersley Group.
Information about the history of the deposit is in short supply, and it appears has always in recent times been the preserve of local specimen miners as small operations. In 2005, David Vaughan discovered one of the largest tiger eye specimens ever at Marra Mamba. It was placed on display at the Tucson Show, and later cut into slabs. One is said to form the counter top of a hotel reception area at Port Hedland. Another the size of a large dining room table is on display at the Kalgoorlie Miners Hall of Fame.
Tiger eye is a golden-brown, chatoyant, siliceous fibre vein, rich in quartz and iron oxides, usually with some riebeckite. It contains multiple bands of green, red, blue, orange jasper, with golden tiger eye, which has a chatoyant effect golden sheen reflected from the fine parallel fibres in the slabs.
Originally it was thought to be a pseudomorph of crocidolite formed by the silica replacement of crocidolite (riebeckite) fibres. Another more recent theory suggests the veins formed as fibrous quartz crystals with interspersed hematite and riebeckite fibres, growing rapidly from the surrounding rocks during low grade metamorphism.
While tiger eye is the most common name, a confusing variety of other names are applied to related material. Hawks eye (blue), falcons eye (green) and pietersite (brecciated) are a few. "Bulls eye" is a heat treated Tiger eye, where the yellow limonite has been converted to red hematite, giving it an overall red colour.
Please be aware 'Tiger Iron' which is the thin banded hematite, jasper, golden tiger eye material, may come from the Ord Ranges in the Port Hedland Shire. Material which is largely 'Tiger Eye' is more likely from the site you are reading this on. Both are showing as pictures under this site, and the material can be compared.
3 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
0 - 2.588 Ma
Age: Pleistocene (0 - 2.588 Ma)
Comments: regolith; synthesis of multiple published descriptions
Reference: Raymond, O.L., Liu, S., Gallagher, R., Zhang, W., Highet, L.M. Surface Geology of Australia 1:1 million scale dataset 2012 edition. Commonwealth of Australia (Geoscience Australia).