Gruzdevite
Gruzdevite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₆Hg₃Sb₄S₁₂.
It crystallizes in the hexagonal crystal system. It is a member of the Nowackiite structural group.
Key properties: specific gravity 5.88; Metallic. Anisotropism: Weak. R: (460) 33.1, (540) 32.8, (580) 32.7, (660) 31.9 luster.
IMA symbol Gzd, IMA status: approved, named in 1980.
Found in veinlets of probable low-temperature hydrothermal origin (Chauvai deposit, Kyrgyzstan).
It is found associated with Aktashite, stibnite, cinnabar, metacinnabar, wurtzite, fluorite, calcite, barite (Chauvai deposit, Kyrgyzstan).
The mineral was named to honor the Russian mineralogist, Vyacheslav Sergeevich Gruzdev (1938–1977), Institute of Mineralogy and Geochemistry of Rare Elements, Moscow, Russia.