Edgarbaileyite

edgarbaileyite

montroydite

terlinguaite

cinnabar

Formula: Hg1+6Si2O7
Sorosilicate (Si2O7 groups)
Crystal System: Monoclinic
Specific gravity: 9.4 measured, 9.11 calculated
Hardness: 4
Streak: Pale green with a yellow tinge
Colour: Freshly exposed material is lemon-yellow to orangish yellow; exposed surfaces range from dark olive-green to a lighter yellowish green to dark green-brown
Solubility: Soluble in cold 1:10 hydrochloric acid, and 1:1 nitric acid
Environments

Hydrothermal environments

Edgarbaileyite is a secondary mineral, probably resulting from reaction between mercury and quartz under unknown conditions. Associated minerals include mercury, cinnabar, montroydite, terlinguaite, eglestonite, calcite, quartz and baryte (HOM, MR 21.215-220).

Localities

At the type locality, Clear Creek claim, Goat Mountain, New Idria Mining District, San Benito county, California, USA, edgarbaileyite occurs as thin crusts on fracture surfaces, disseminated rounded to mammillary masses, and hollow mammillary nodules. It is most closely associated with native mercury and montroydite in a host rock composed principally of quartz, magnesite and chalcedony. Other associated minerals include terlinguaite, quartz, eglestonite, cinnabar, calcite and baryte. Edgarbaileyite is one of the latest minerals in the paragenetic sequence and is found near the centre of the quartz veins that transect the host rock (MR 21.215-220, Mindat).

At the Socrates Mine, Castle Rock Springs area, West Mayacmas Mining District, Sonoma county, California, USA, edgarbaileyite has been identified as thin crusts on fracture surfaces, as disseminated rounded to mammillary masses in small cavities, and as hollow mammillary nodules; it is most closely associated with chalcedony, native mercury, cinnabar and montroydite in a host rock composed principally of magnesite and quartz. Edgarbaileyite has been found replacing quartz crystals in situ. It is one of the latest minerals in the paragenetic sequence and is found near the centre of the quartz veins that transect the host rock. Some veinlets of edgarbaileyite have been found that were altered to a homogeneous mixture of montroydite and quartz (MR 21.215-220).

At Terlingua, Brewster County, Texas, USA, edgarbaileyite occurs on a museum specimen as ill-formed tabular aggregates and sheaves of crystals in cavities and fractures; it consists of intergrown chrystals of montroydite, terlinguaite, eglestonite and edgarbaileyite in a matrix of calcite, quartz and baryte (Minrec 21.215-220).

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