Harmotome

Harmotome
General
CategoryTectosilicate minerals, zeolite group, phillipsite subgroup
Formula(Ba2(Si12Al4)O32·12H2O
IMA symbolHrm
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/m
Identification
Specific gravity2.44 to 2.5

Harmotome is a mineral, one of the rarer zeolites; a hydrated barium silicate with formula: (Ba2(Si12Al4)O32·12H2O. It forms vitreous white well defined monoclinic crystals, often associated with calcite and other zeolites. It has a Mohs hardness of 4 to 5 and a specific gravity of 2.44 to 2.5.