THE MINERAL AUSTINITE

Chemistry: CaZnAsO4OH, Calcium Zinc Arsenate Hydroxide
Class: The Phosphates
Subclass: Arsenates
Group: Adelite
Uses: Only as mineral specimens.
Specimens

Austinite is fairly rare but popular collection mineral. It forms in the oxidation zone of zinc ore deposits, often with the sometimes similar looking adamite. It can have a very nice color and silky or sub-adamantine (almost gem-like) luster. Fine specimens occur as radial clusters of intensely green crystals, and are much in demand.

Austinite is named after the mineralogist Austin F. Rogers.

PHYSICAL CHARACTERISTICS:

Color is typically a bright green, but also colorless, white or pale yellow.
Luster is sub-adamantine or silky.
Transparency: Crystals are transparent to translucent.
Crystal System is orthorhombic; 2/m 2/m 2/m
Crystal Habits include acicular or bladed crystals in druses, radial aggregates or crusts, also fibrous.
Cleavage is perfect in one direction lengthwise.
Fracture is uneven.
Hardness is 4 - 4.5.
Specific Gravity is approximately 4.1 (heavy for translucent minerals)
Streak is white to pale green.
Associated Minerals are adamite, legrandite, limonite, smithsonite, aragonite and other oxidation zone minerals.
Notable Occurrences include Mapimi, Mexico; Tsumeb, Namibia and Toole Co., Utah, USA.
Best Field Indicators are crystal habit, cleavage, color, luster, density, lack of fluorescence and associations.