Fülöppit im Museum für Naturkunde Berlin Fundort: Baia-mare in Maramures — Photo: Oceancetaceen Alice Chodura · CC BY-SA 3.0
Fülöppite
A rare plagionite-group lead-antimony sulfosalt named in 1929 for Hungarian lawyer and collector Béla Fülöpp.
Intro adapted from Wikipedia (CC BY-SA).
Fülöppite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₃Sb₈S₁₅.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 2.5; specific gravity 5.22; Reddish gray streak; Metallic. Anisotropism: May be weak in bluish gray, moderate in blue-green to red-brown. R1 –R2: (400) 37.8–45.9 luster.
IMA symbol Fül, grandfathered status — known before the IMA’s founding, named in 1929.
Hydrothermal in origin.
It is found associated with Zinkenite, semseyite, fizélyite, andorite, freieslebenite, geocronite, boulangerite, jamesonite, cinnabar, sphalerite, marcasite, quartz, dolomite.
The name refers to Dr. Béla Fülöpp (1863–1938), mineral collector of Hungary.