Jacutingaite from Figure 3 , in dolomite matrix. The image is published in an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( https://creativecommons.org/licenses/by/4.0/ ). — Photo: Chi Ma, Hans-Jürgen Förster and Günter Grundmann · CC BY 4.0
Jacutingaite
Jacutingaite is an IMA-recognized mineral species in the sulfide class, with the chemical formula Pt₂HgSe₃.
It crystallizes in the hexagonal crystal system (space group P-3m1). It is a member of the Jacutingaite structural group.
Key properties: Mohs hardness 3.5; specific gravity 10.9; Gray [Synthetic] streak; Metallic luster.
IMA symbol Jac, IMA status: approved, named in 2010.
Found in heavy-mineral concentrate from a friable, hematite-rich auriferous vein that cuts metamorphosed banded iron formation.
It is found associated with Potarite, atheneite, hematite.
The name commemorates vein-type gold mineralization rich in specular hematite, known as “jacutinga” in Minas Gerais, Brazil.