Although adamite occurs in many localities, it’s very rarely cut as a gem. This mineral is much too soft and fragile for jewelry. However, collectors prize its intense fluorescence.
Adamite
Information
Data
Value
Name
Adamite
Formula
Zn2(AsO4)OH + Co, Cu
Etymology
After Gilbert-Joseph Adam, the Parisian mineralogist who supplied the first specimens for study.
Occurrence
Secondary mineral in the oxidized zone of ore deposits.
Colorless; yellowish green, yellow in various shades (contains Fe); pale green, bluish green, green (contains Cu); rose and violet shades (color zoned, contains Co); purple (contains Mn).
Adamite forms a series, as the zinc (Zn) analogue, with olivenite, the copper (Cu) analogue. This series has a distinct, intermediate member known as zincolivenite. (Don’t confuse olivenite with olivine).
The presence of numerous impurities can create various colors in adamites. For example, iron (Fe) can cause yellow hues. Cuprian (Cu bearing) varieties show green hues. Cobalt (Co) bearing specimens can show rose or purple/violet hues. Manganoan or manganese (Mn) bearing specimens may have purple/violet colors as well as pink and lavender.
Manganoan adamite and lotharmeyerite, Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico. Photo by Didier Descouens. Licensed under CC By-SA 3.0. (Lotharmeyerite occurs here as tiny, dark red crystals).
Identifying Characteristics
Adamites can have an intense green fluorescence under either shortwave (SW) or longwave (LW) ultraviolet light. They may also show lemon yellow fluorescence under SW.
Scientists have used synthetic specimens of the adamite-olivenite series for spectroscopy research. However, there is no known jewelry use for this material.
The Ojuela Mine in Mapimi, Mexico produces fine sprays of crystals in limonite matrix.
Tsumeb, Namibia also produces fine crystals, sometimes colored purple by cobalt.
Laurium, Greece yields specimens often containing copper, in lovely blue and green shades.
Other notable sources include:
United States: California; Nevada; Utah (various localities).
France: Cap Garonne.
Algeria; Chile; Germany; Italy; Turkey.
Stone Sizes
Violet crystals, noted up to 1 cm long and transparent, would yield stones up to about 1-2 carats. Green material, usually not clean, would provide only small faceted gems (1-3 carats).
Private Collection: 4.38 (pink, Mexico).
Care
Adamites have a low hardness of 3.5 and good cleavage. Thus, they make less than optimal pieces for jewelry use. You’ll find these stones more likely in gem collections as crystal specimens than in jewelry collections. See our gemstone jewelry cleaning guide for care recommendations.