Mineral Database
Tschermigite
Crystal System: Cubic
Formula: NH4Al(SO4)2.12H2O
Status of Occurrence: Confirmed Occurrence - 2nd UK recording
Distribution: Rare
Chemical Composition: Hydrated ammonium-aluminium sulphate
Method(s) of Verification: Two-Feet-Nine Seam, Deep Navigation Colliery, Treharris - identified by XRD at the National Museum of Wales (XRD no. NMW X-1944).
Chemical Group:
- Sulphates
Introduction: an uncommon secondary sulphate mineral in some coal deposits or as efflorescence associated with fumaroles and hot springs.
Occurrence in Wales: colourless crystallized tschermigite was identified on a specimen of epsomite from Deep Navigation Colliery during a study of halotrichite group minerals from Wales (Cotterell, 2009).
Key Localities:
- Deep Navigation Colliery, Treharris, South Wales: colourless crystallized tschermigite occurs intergrown with massive opaque white epsomite on a specimen from the Two-Feet-Nine Seam, Deep Navigation Pit donated by T. Gwilt Cotsworth to the National Museum of Wales specimen in 1927 and accessioned as NMW 27.128.GR.2 (Cotterell, 2009).
References:
- A review of halotrichite group minerals in Wales. UK Journal of Mines and Minerals, 30, 43-47.
