Mineral
Adamita
Zn₂AsO₄(OH) · Arseniatos
Adamite is a secondary zinc hydroxyarsenate that crystallises in the orthorhombic system and occurs in the oxidation zones of zinc–lead deposits.
It belongs to the eponymous group. In these settings it is typically associated with limonite, smithsonite and hemimorphite. It occurs as botryoidal or prismatic aggregates. Under ultraviolet light it shows green fluorescence, often due to uranyl traces.
Adamite is usually colourless, though an uncommon lemon-yellow colour also occurs. A yellow‑green variety owes its hue to traces of copper. Partial substitution of zinc by copper produces cuproadamite, green in colour. At Ojuela Mine, adamite commonly shows that lemon yellow and intense green fluorescence linked to uranyl.
Etymology
A classic etymological false friend: although it shares the root "adamas" with diamond, adamite is simply named in honour of Gilbert-Joseph Adam, who brought the first samples from Chañarcillo, the type locality that allowed the species to be identified.
Specimens in the collection (6)
- Adamita — Mina Ojuela, Mapimí, Durango, México № 0038
- Adamita — Mina Ojuela, Mapimí, Durango, México № 0144
- Adamita — Mina Ojuela, Mapimí, Durango, México № 0215
- Adamita (Cuprífera) — Hilarion Mine / Kamariza Mines, Agios Konstantinos, Lavreotiki, Ática, Grecia № 0280
- Adamita — Mina Ojuela, Mapimí, Durango, México № 0406
- Adamita — Mina Ojuela, Mapimí, Durango, México № 0411