Black crystals of the very rare mercury mineral hypercinnabar. Hypercinnabar has only been found in 6 localities worldwide. Analyzed specimen. From: Clear Creek, San Benito County, California, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Hypercinnabar
Hypercinnabar is an IMA-recognized mineral species in the sulfide class, with the chemical formula HgS.
It crystallizes in the hexagonal crystal system.
Key properties: Mohs hardness 3; specific gravity 7.43; Dark black-purple streak; Adamantine. Anisotropism: Distinct in oil. R1 –R2: n.d luster.
IMA symbol Hcin, IMA status: approved, named in 1977.
Intimately in association with metacinnabar, which it generally resembles.
It is found associated with Metacinnabar.
In allusion to the fact that the stability field of the species extends to higher temperatures than that of cinnabar or metacinnabar.