Adamite is a zinc arsenate hydroxide mineral, Zn<sub>2</sub>AsO<sub>4</sub>OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is an intermediate mineral with formula CuZn(AsO<sub>4</sub>)(OH). Manganese, cobalt, and nickel also substitute in the structure. Tarbuttite is an analogous zinc phosphate.
thumb|left|Adamite on limonite from the Gold Hill District [[Tooele County, Utah, US. Scale at bottom is 2.5 cm.]]
Occurrence
Adamite occurs as a secondary mineral in the oxidized zone of zinc- and arsenic-bearing hydrothermal mineral deposits. It occurs in association with smithsonite, hemimorphite, scorodite, olivenite, calcite, quartz and iron and manganese oxides.