Adamite is a zinc arsenate famous for its vivid yellow-green to lime-green fluorescent crystals from Mexico. It is the zinc analogue of olivenite (the copper arsenate) and forms one of the most photogenic secondary minerals.
Properties
- Formula: Zn2(AsO4)(OH)
- Crystal system: Orthorhombic
- Hardness: 3.5
- Color: Yellow-green, lime, white, pink (Co-bearing), purple (Cu-Mn rich)
- Streak: White
- Luster: Vitreous
- Cleavage: Good on {101}
- Density: 4.3 – 4.4 g/cm³
Occurrence
The world’s premier locality is Mina Ojuela, Mapimí (Durango, Mexico) — radiating sprays and druzy plates of intensely fluorescent yellow-green adamite on goethite/limonite. Also at Lavrion (Greece) for cuprian/cobaltian color varieties. Tsumeb (Namibia) produces purple cuprian adamite.
Identification
Lime-yellow color + bright SW UV fluorescence (distinctive lemon-green) + association with Mn-Fe oxides + Mapimí pedigree. Distinguish from olivenite (similar habit but green-olive Cu chemistry) and willemite (silicate, harder).
Collector Notes
Mapimí adamite is one of the most popular Mexican collector minerals worldwide. Cobaltian (pink) and cuprian (purple) varieties command premium prices.
Found at these Localities
- Lavrion (Laurium) (拉夫里翁古铅锌银矿)
- Tsumeb Mine (楚梅布矿)
- Mina Ojuela, Mapimí (马皮米奥胡埃拉矿)
