Austinite

From the Tsumeb mine in Namibia, light, lustrous, limey-grass green micro-crystals of the rare calcium-zinc arsenate Austinite richly coat an undulating, dark olive-green surface of what is most probably Olivenite micro-crystals forming a botryoidal surface. This association covers a roughly 3.0 x 1.5 cm area at one end of the specimen and under a magnification of, say, x20 to x25, hundreds of perfect Austinite crystals are visible. The rest of the specimen’s display surface is composed of small rhombohedral Calcite crystals averaging 2 to 3 mm in length and totally included with Austinite of the same colour. A fine specimen of this rare mineral.