Romanèchite

Composition: (Ba,H2O)2(Mn4+,Mn3+)5O10
Crystal System : Monoclinic
Colours: Black
Lustre : Sub-metallic, dull
Hardness (H) : 5-6
Specific Gravity (S.G) : 4.71
References: Gebhard (1999)

  

Distribution

Very rare. Questionable status at Tsumeb. 

Occurrence

  • Supergene

Paragenetic and General Notes

Listed by both Lombaard et al. (1986) and Gebhard (1999) as a questionable occurrence at Tsumeb.  However, Gebhard (op. cit.) suggests that romanèchite is one of the component minerals in the black, manganese oxide coatings sometimes observed on calcite and mottramite.