White carbonate mineral
Hydrozincite Category Carbonate mineral Formula (repeating unit) Zn5 (CO3 )2 (OH)6 IMA symbol Hznc[ 1] Strunz classification 5.BA.15 Crystal system Monoclinic Crystal class Prismatic (2/m) (same H-M symbol ) Space group C2/m Unit cell a = 13.58 Å, b = 6.28 Å, c = 5.41 Å; β = 95.51°, Z = 2 Color White to grey, stained pale pink, or pale yellow or brown; colourless in transmitted light. Crystal habit Lathlike or bladed crystals uncommon, in fibrous, stalactitic, reniform, pisolitic aggregates; also earthy, chalky, massive Twinning Contact twinning on {100} Cleavage Perfect on {100} Fracture Irregular/uneven Tenacity Very brittle Mohs scale hardness 2–2+ 1 ⁄2 Luster Silky, pearly, dull, earthy Streak White Diaphaneity Transparent, translucent Specific gravity 3.5–4 Optical properties Biaxial (−) Refractive index nα = 1.630 nβ = 1.642 nγ = 1.750 Birefringence δ = 0.120 2V angle Measured: 40°, calculated: 40° Dispersion relatively strong Ultraviolet fluorescence Fluoresces pale blue to lilac under UV Solubility Readily soluble in acids. References [ 2] [ 3] [ 4]
Hydrozincite , also known as zinc bloom or marionite , is a white carbonate mineral consisting of Zn 5 (CO3 )2 (OH )6 . It is usually found in massive rather than crystalline form.
It occurs as an oxidation product of zinc ores and as post mine incrustations. It occurs associated with smithsonite , hemimorphite , willemite , cerussite , aurichalcite , calcite and limonite .[ 2]
It was first described in 1853 for an occurrence in Bad Bleiberg , Carinthia , Austria and named for its chemical content.[ 3]
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