A lot of single white crystals of the very rare amonium mineral teschemacherite from one of the only 4 localities known wordwide in a capsule. From North Chincha Island, Pisco Province, Ica Department, Peru. Analyzed specimen by SEM/EDS. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Teschemacherite
Teschemacherite is an IMA-recognized mineral species in the carbonate class, with the chemical formula (NH₄)H(CO₃).
It crystallizes in the orthorhombic crystal system (space group Pccn).
Key properties: Mohs hardness 1.5; specific gravity 1.45; optically biaxial.
IMA symbol Tmh, grandfathered status — known before the IMA’s founding, named in 1868.
Rarely found in guano deposits.
The mineral was named to honor Frederick Edward Teschemacher (1791–1863), English chemist, who first described the species.