Crocoite with Gibbsite specimen - Adelaide mine in Tasmania

Crocoite and gibbsite specimens from the Adelaide Mine in Tasmania are known for their striking appearance and mineralogical interest.

1.Crocoite

- Composition: Crocoite is a lead chromate mineral with the chemical formula PbCrO₄.

- Appearance: It often forms bright red to orange crystals that can be quite striking. These crystals are usually elongated and can occur in clusters.

- Formation: Crocoite forms in the oxidation zones of lead-chromium deposits, and its vivid color is due to chromium.

2. Gibbsite
- Composition: Gibbsite is a mineral form of aluminum hydroxide with the formula Al(OH)₃.

- Appearance It typically appears as white, gray, or colorless crystals or masses, and it can have a somewhat dull or earthy luster.

- Formation: Gibbsite forms in bauxite deposits and can be associated with tropical and subtropical weathering processes.

Adelaide Mine (Tasmania)

- Location: The Adelaide Mine is situated in the Zeehan district on the west coast of Tasmania.

- Historical Context: The mine was historically significant for its lead and silver production.

- Mineral Specimens: The mine is famous for producing high-quality cocoite specimens, which are among the best in the world due to their brilliant coloration and well-formed crystals. Gibbsite can also be found in the area, though it is less commonly noted compared to crocoite.

Combining crocoite with gibbsite in specimens from this region provides a fascinating contrast between the vivid reds of crocoite and the more subdued, earthy tones of gibbsite.