Hemimorphite (Zn₄Si₂O₇(OH)₂·H₂O) is a hydrous zinc silicate that forms in the oxidized cap zones of zinc-bearing ore deposits, frequently as a botryoidal blue-green encrustation directly above smithsonite. It is named for its hemimorphic crystals — pyramidal at one end and flat at the other, a rare “polar” symmetry caused by its non-centrosymmetric orthorhombic crystal structure.
Key Facts
- Mohs hardness 4.5–5.
- Strikingly blue-green botryoidal habit is its most-collected form.
- Rare prismatic crystals show classic hemimorphic asymmetry.
- Pyroelectric and piezoelectric — exhibits charge under heat or pressure.
- Typically forms together with smithsonite, sphalerite, calcite, and aurichalcite in oxidized zinc deposits.
Notable Chinese Localities
Wenshan (Yunnan) produces world-class blue botryoidal hemimorphite that is often paired with smithsonite. Guangxi and Hunan also yield collector material from their zinc oxidation zones.
Found at these Localities
- Lavrion (Laurium) (拉夫里翁古铅锌银矿)
- Bisbee (Warren District) (比斯比铜矿)
- Mina Ojuela, Mapimí (马皮米奥胡埃拉矿)
- Yunnan (云南)
- Guangxi (广西)
- Hunan (湖南)
Available Products of Hemimorphite
5 available specimens
