Mineral Species
Sepiolite
Type Locality
No
Composition
Mg4Si6O15(OH)2·6H2O
Crystal System
Orthorhombic
Status at Tsumeb
Believed valid
Abundance
Extremely rare
Distribution
Undetermined
Paragenesis
Supergene
Entry Number
Species; TSNB316
General Notes
Sepiolite from Tsumeb was first reported by Belendorff (2006) as an accessory mineral accompanying brucite in earthy crusts in a rare paragenesis for which the following crystallisation sequence was proposed:
cerussite (w. hydrocerussite) >> wulfenite >> dolomite >> parkinsonite >> calcite(rhombohedral) >> brucite >> sepiolite >> calcite(scalenohedral).
No other occurrences have been reported but sepiolite would be readily overlooked.
Associated Minerals
brucite; calcite; cerussite; dolomite; hydrocerussite; parkinsonite; wulfenite
