| Hydrozincite | |
| Category: | Carbonate mineral |
| Formula: | Zn5(CO3)2(OH)6 |
| Imasymbol: | Hznc[1] |
| Strunz: | 5.BA.15 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | 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. |
| Habit: | Lathlike or bladed crystals uncommon, in fibrous, stalactitic, reniform, pisolitic aggregates; also earthy, chalky, massive |
| Twinning: | Contact twinning on |
| Cleavage: | Perfect on |
| Fracture: | Irregular/uneven |
| Tenacity: | Very brittle |
| Mohs: | 2– |
| Luster: | Silky, pearly, dull, earthy |
| Streak: | White |
| Diaphaneity: | Transparent, translucent |
| Gravity: | 3.5–4 |
| Opticalprop: | Biaxial (−) |
| Refractive: | nα = 1.630 nβ = 1.642 nγ = 1.750 |
| Birefringence: | δ = 0.120 |
| 2V: | Measured: 40°, calculated: 40° |
| Dispersion: | relatively strong |
| 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 Zn5(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]