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