Crocoite, Adelaide Mine, Dundas, Tasmania Revisited

Mineral Matters #416

A few days ago, I mentioned that I was dropping in to see Adam Wright (Adelaide Mining Company) who mines crocoite at the Adelaide Mine, Dundas, on the west coast of Tasmania.

Adam has still been finding crocoite, which is great. Most of the current production is coming from what Adam calls the Red River Falls.

He has also been finding some other interesting stuff which is in the process of being analysed. One is tiny crocoite crystals on a purplish botryoidal matrix, likely to be maybe gibbsite. Perhaps the colour is from chromium, similar to stichtite. The other is a sulphide. Adam thought maybe acanthite or tetrahedrite. But having looked at a piece under my microscope, I see sphalerite with possibly a coating of galena. Anyway, it will be interesting to find out.

A specimen that I came back with (below) has a later generation of very lustrous and gemmy smaller crocoite crystals attached to the larger crocoite crystals.

Below: A specimen from this year’s production. Width of specimen about 50mm.