Small rounded crystals of the extremely rare mercury mineral grumiplucite, associated to cinnabar and mercury. Type and only locality known worldwide!! Ex-"Not Only Stones" specimen. Identification by the team of "Not-Only-Stones" (Italy). From: Levigliani Mine, Stazzema, Lucca Province, Tuscany, Italy. — Photo: David Hospital · CC BY-SA 4.0
Grumiplucite
Grumiplucite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula HgBi₂S₄.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Pavonite structural group.
Key properties: specific gravity 7.02; Metallic luster.
IMA symbol Gpc, IMA status: approved, named in 1997.
Very rare, in quartz-carbonate veins in mercury deposist, probably developed during retrograde metamorphism.
It is found associated with Cinnbar, mercurian sphalerite, mercury, pyrite (Italy); cinnabar, tetrahedrite, chalcopyrite, arsenopyrite, siderite, baryte (Slovakia).
The name refers to the GRUppo MIneralogico e Paleontological LUcchese, a group of amateur mineralogists who provided the specimens for study.