Mercury

mercury

cinnabar

calomel

terlinguaite

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Formula: Hg
Native element, transition metal, may be monovalent Hg+1 or divalent Hg+2
Crystal System: Trigonal
Specific gravity: 13.596 measured
Hardness: Liquid
Streak: Liquid
Colour: Tin-white
Common impurities: Au,Ag
Abundance in the Earth's crust: 85 parts per billion by mass, 9 parts per billion by moles (CHC)
Abundance in the Solar System: 20 parts per billion by mass, 120 parts per trillion by moles (CHC)
HIGHLY TOXIC
Environments

Sedimentary environments
Hydrothermal environments
Hot springs

Native mercury is a secondary mineral resulting from oxidation of cinnabar deposits. It is solid below -38.9°C (Webmin). Although under ambient conditions mercury is liquid and so technically it does not qualify as a mineral, the IMA makes an exception and recognises it as one. It is usually found as small isolated drops associated with cinnabar, but it can also be found as large liquid masses in rock cavities; it is often found, along with cinnabar and other mercury minerals, as a precipitate from hot springs, in volcanic regions and in hydrothermal deposits formed at low temperature. Associated minerals include cinnabar, metacinnabar, calomel, terlinguaite, eglestonite, mercury-bearing silver, mercury-bearing gold, pyrite, dolomite, baryte and quartz (HOM, Mindat).

Localities

The Rutland Cavern, Heights of Abraham, Matlock Bath, Derbyshire Dales District, Derbyshire, England, UK, is a show cave in limestone. The specimen on which native mercury has been observed consists of a 5 x 3 x 1.5 cm piece of calcite matrix with included galena. A cavity in the calcite containing smithsonite was observed to carry silvery globules of mercury measuring about 0.05 to 0.1 mm in diameter.
The cinnabar at Rutland Cavern is closely associated with smithsonite formed from the alteration of sphalerite, and was probably a component of the sphalerite either in solid solution or as inclusions. Being more resistant to oxidation than the sphalerite, the cinnabar remained intact during sphalerite oxidation. The sulphur in sphalerite is oxidised at pH conditions near 8 (mildly alkaline) at Eh values (see Pourbaix diagrams) above about -0.2, leading to the release of zinc ions, which in the carbonate rich environment forms smithsonite at around the conditions required for forming native mercury (JRS 15.75-76).

At the Hilderston Silver Mine, Linlithgow, West Lothian, Scotland, UK, micron-sized particles of mercury have been reported, closely associated with acanthite (JRS 15.75-76).

At the Clear Creek claim, Goat Mountain, New Idria Mining District, San Benito county, California, USA, droplets and coatings of native mercury fill cavities and veins throughout the mine, often in volumes exceeding 1 ml. Associated minerals include cinnabar, edgarbaileyite, eglestonite, montroydite, mosesite, szymanskiite and wattersite. Most native mercury has been found either filling isolated cavities in quartz veins or associated with cinnabar as vein fillings. The mercury shows strong affinity for quartz (Minrec 36.4.347-348).

At the Moon Anchor mine, Cripple Creek Mining District, Teller county, Colorado, USA, native mercury has been reported in small amounts associated with cinnabar and coloradoite (Minrec 36.2.174).

At the Huron River Uranium Prospect, Baraga County, Michigan, USA, native mercury is rare. A solitary, 0.1 mm, metallic drop of liquid mercury was observed on a single specimen associated with mercury-bearing silver, chalcopyrite, bornite and other sulphides (R&M 87-2.134-139).

Mercury-bearing minerals include:

Alloys
leadamalgam
potarite

Sulphides
atheneite
cinnabar
donharrisite
hypercinnabar
imiterite
kenhsuite
metacinnabar
radtkeite
tennantite-(Hg)

Selenides
tiemannite

Tellurides
coloradoite
temagamite

Sulphosalts
aktashite
gruzdevite
hakite-(Hg)
laffittite
livingstonite
routhierite
vaughanite
vrbaite

Oxides
montroydite

Halides
calomel
corderoite
eglestonite
hanawaltite
kadyrelite
kelyanite
kleinite
kuzminite
lavrentievite
mikecoxite
moschelite
mosesite
poyarkovite
terlinguaite

Carbonates
szymanskiite

Sulphates
gianellaite

Chromates
edoylerite
wattersite

Phosphates
artsmithite

Arsenates
chursinite
kuznetsovite

Sorosilicates
edgarbaileyite

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