sustinite

Sustinite is a name that has appeared in mineralogical literature as a proposed mineral species, but it is not recognized by the International Mineralogical Association (IMA) in the current master lists. The absence of a formal description—no verified chemical composition, crystallography, or locality data—means there is no accepted set of diagnostic properties for sustinite. In many references, the term has been encountered as either a provisional name, a misidentification, or a local nickname for another mineral. Because of this uncertainty, reliable identification of sustinite in hand specimens or polished sections is not possible without access to the original description or subsequent peer-reviewed validation.

The lack of recognition means there is no widely accepted standard for its occurrence, paragenesis, or physical properties such as hardness, color, luster, cleavage, or crystal system. It is also not listed with a confirmed IMA number or formula. For researchers or collectors encountering the term, the recommended approach is to consult authoritative databases such as Mindat.org and the IMA List of Minerals, and to try to locate the original descriptive publication or the local collectors' report that used the name. If sustinite is indeed a valid mineral name, a formal description and a proper type specimen designation would eventually be published to secure its status.