Hemimorphite

“Two-faced zinc silicate”

Mineral

Hemimorphite is a zinc silicate mineral that forms in the oxidation zones of zinc deposits. Its most distinctive feature is hemimorphism — each crystal has a different shape at either end, with a pointed termination on one side and a flat, blunt pedion on the other.

Composition

zinc silicate hydroxide (Zn₄Si₂O₇(OH)₂·H₂O)

Where Found

Mapimí (Mexico), Wenshan (China), Vieille Montagne (Belgium), Bleiberg (Austria), Zambia, New Mexico (USA)

Mohs Hardness

4.5-5

Fun Fact

Hemimorphite is both piezoelectric and pyroelectric — squeezing or heating a crystal generates opposite electrical charges at its two different ends, turning it into a natural battery.