Mineralpedia Details for Metacinnabar
Named for its general association with cinnabar, and the prefix meta- in this instance refers to the Greek translation which means “with.” Metacinnabar is found in mercury deposits that formed under low-temperature and near-surface conditions. Localities for Metacinnabar include in the United States, Canada, Slovenia, Italy, Spain, Russia, and China, among others.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/metacinnabar.pdf
Metacinnabar from Mount Diablo mine, Contra Costa Co., California, United States
Blackish or deep red micro crystals to 0.75mm