Outstanding shiny black crystals of the extremely rare cadmium mineral monteponite from the famous Kudriavy volcano (Iturup Island, Sakhalinskaya Obl, Far Eastern Region, Russian Federation). Cadmium minerals are very rare in Nature, since only 27 from more than 5000 mineral species known are cadmium minerals. Specimen analyzed by SEM/EDS. — Photo: David Hospital · CC BY-SA 4.0
Monteponite
Monteponite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula CdO.
It crystallizes in the cubic crystal system (space group Fm3m).
Key properties: Mohs hardness 3; specific gravity 8.1–8.2; Brilliant luster.
IMA symbol Mtp, grandfathered status — known before the IMA’s founding, named in 1901.
Found as a coating over “calamine” (Genarutta mine, Sardinia, Italy); in sulfide ore (Verkhoyan’ya, Russia). In altered pyrometamorphic rocks (Jordan).
It is found associated with “Calamine” [smithsonite or hemimorphite] (Genarutta mine, Sardinia, Italy); cadmium, otavite (Verkhoyan’ya, Russia).
The name refers to Monteponi, near the locality on Sardinia, Italy.