Class: Carbonates (Nitrates)
Group: Calcite
A secondary mineral formed in the oxidised zone of zinc-bearing deposits and replacing adjacent carbonate rocks (
Anthony et al., 2001—2005).
Original description: Beudant, F. S., 1832. Smithsonite, Zinc carbonaté — Traité Élémentaire de Minéralogie, Paris: 354—357 [
view in ‘Library’].
Type locality: United Kingdom of Great Britain and Northern Ireland.
Type material: unknown.
Etymology: in honour of James Lewis Smithson, British chemist and mineralogist, whose bequest founded the Smithsonian Institution, Washington, DC.
Distribution: many localities: Austria; Belgium; France; Germany; Greece; Italy: Sardinia; Mexico: Chihuahua; Namibia: Tsumeb; Poland; USA; Zambia (
Anthony et al., 2001—2005).
Chemistry
ZnCO3
Essential elements: carbon (C), oxygen (O), zinc (Zn).
Crystal data
Crystallography: trigonal — hexagonal scalenohedral.
Crystal habit: uncommon as crystals, to 10 cm, rhombohedral and scalenohedral; typically botryoidal, reniform; earthy, friable, granular to porous or massive (
Anthony et al., 2001—2005).
Optical properties
Colour: white, pale grey, dark grey, pale brown, brown, more rarely pale shades of red, pink, orange, yellow, green, apple-green, emerald-green, blue, bluish grey; colourless to faintly tinted in transmitted light (
Anthony et al., 2001—2005).
Diaphaneity: transparent to translucent (
Anthony et al., 2001—2005).
Lustre: vitreous, pearly (
Anthony et al., 2001—2005).
Refractive index: 1.62—1.85 — anisotropic [uniaxial (-)] (
Lazzarelli, 2012).
Birefringence: 0.227.
Dispersion: 0.037 (
Arem, 1987: 174).
Pleochroism: none.
Material from ‘Repository’
