paradamite

{{Infobox mineral | name = Paradamite | image = Paradamite-Ojuela Mine-Romero.jpg | caption = Paradamite from the Ojuela Mine, Mapimí, Durango, Mexico | boxbgcolor = #ffee8c | category = Arsenate minerals | formula = Zn2(AsO4)(OH) | IMAsymbol = Prd | strunz = 8.BB.35 | system = Triclinic | symmetry = P1 | color = Pale to lemon yellow, yellow-orange; rarely white | habit = Sheaf-like aggregates; blocky or lozenge-shaped crystals | cleavage = Perfect on {010} | tenacity = Brittle | mohs = 3.5 | luster = Vitreous to sub-vitreous, resinous | streak = White | diaphaneity = Transparent to translucent | gravity = 4.55 (measured) | opticalprop = Biaxial (–) | refractive = nα = 1.726, nβ = 1.771, nγ = 1.780 | birefringence = 0.054 | 2V = Measured: 50°; calculated: 46° | dispersion = Relatively strong }}

Paradamite is a very rare zinc arsenate mineral with the chemical formula Zn2(AsO4)(OH). It is closely related to the better-known mineral adamite: both have the same chemical composition, but the atoms are arranged differently in the crystals. Because of this different structure, paradamite and adamite belong to different crystal systems (triclinic for paradamite, orthorhombic for adamite) and are considered polymorphs of each other.