Montroydite | |
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General | |
Category | Oxide mineral |
Formula (repeating unit) | HgO |
IMA symbol | Mtyd [1] |
Strunz classification | 4.AC.15 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M Symbol: (2/m 2/m 2/m) |
Unit cell | a = 5.52 Å, b = 6.6 Å, c = 3.52 Å; Z=4 |
Identification | |
Color | Deep red, brownish red to brown |
Crystal habit | Long prismatic, equant, rarely flattened; striated; massive to vermicular clusters |
Cleavage | Perfect {010} |
Tenacity | Sectile |
Mohs scale hardness | 1.5 - 2.0 |
Luster | Sub-adamantine, vitreous |
Streak | Yellow brown |
Diaphaneity | Transparent to translucent |
Specific gravity | 11.23 |
Optical properties | Biaxial (+) |
Refractive index | nα = 2.370 nβ = 2.500 nγ = 2.650 |
Birefringence | δ = 0.280 |
Pleochroism | Deep red-orange to yellowish brown (visible in thick sections) |
2V angle | Large |
References | [2] [3] |
Montroydite is the mineral form of mercury(II) oxide with formula HgO. It is a rare mercury mineral. It was first described for an occurrence in the mercury deposit at Terlingua, Texas and named for Montroyd Sharp who was an owner of the deposit. [2]
Montroydite occurs in mercury deposits of hydrothermal origin. Associated minerals include: native mercury, cinnabar, metacinnabar, calomel, eglestonite, terlinguaite, mosesite, kleinite, edgarbaileyite, gypsum, calcite and dolomite. [3]
Cinnabar, or cinnabarite, is the bright scarlet to brick-red form of mercury(II) sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic).
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains the most important source of tin today.
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
The mineral petzite, Ag3AuTe2, is a soft, steel-gray telluride mineral generally deposited by hydrothermal activity. It forms isometric crystals, and is usually associated with rare tellurium and gold minerals, often with silver, mercury, and copper.
Calomel is a mercury chloride mineral with formula Hg2Cl2 (see mercury(I) chloride). The name derives from Greek kalos (beautiful) and melas (black) because it turns black on reaction with ammonia. This was known to alchemists.
Lorándite is a thallium arsenic sulfosalt with the chemical formula: TlAsS2. Though rare, it is the most common thallium-bearing mineral. Lorandite occurs in low-temperature hydrothermal associations and in gold and mercury ore deposits. Associated minerals include stibnite, realgar, orpiment, cinnabar, vrbaite, greigite, marcasite, pyrite, tetrahedrite, antimonian sphalerite, arsenic and barite.
Terlinguaite is the naturally occurring mineral with formula Hg2ClO. It is formed by the weathering of other mercury-containing minerals. It was discovered in 1900 in the Terlingua District of Brewster County, Texas, for which it is named. Its color is yellow, greenish yellow, brown, or olive green.
Tiemannite is a mineral, mercury selenide, formula HgSe. It occurs in hydrothermal veins associated with other selenides, or other mercury minerals such as cinnabar, and often with calcite. Discovered in 1855 in Germany, it is named after Johann Carl Wilhelm Tiemann (1848–1899).
Clausthalite is a lead selenide mineral, PbSe. It forms a solid solution series with galena PbS.
Corderoite is an extremely rare mercury sulfide chloride mineral with formula Hg3S2Cl2. It crystallizes in the isometric crystal system. It is soft, 1.5 to 2 on the Mohs scale, and varies in color from light gray to black and rarely pink or yellow.
Hectorite is a rare soft, greasy, white clay mineral with a chemical formula of Na0.3(Mg,Li)3Si4O10(OH)2.
Atheneite is a rare palladium, mercury arsenide mineral with the chemical formula (Pd,Hg)3 associated with palladium–gold deposits. Its composition parallels that of arsenopalladinite, isomertieite and meritieite-II.
Mosesite is a very rare mineral found in few locations. It is a mercury mineral found as an accessory in deposits of mercury, often in conjunction with limestone. It is known to be found in the U.S. states of Texas and Nevada, and the Mexican states of Guerrero and Querétaro. It was named after Professor Alfred J. Moses (1859–1920) for his contributions to the field of mineralogy in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of spinel twinning. It becomes isotropic when heated to 186 °C (367 °F).
Clearcreekite is a carbonate mineral, polymorphous with peterbaylissite. The chemical formula of clearcreekite is Hg(1+)3CO3(OH)∙2H2O. It has a pale greenish yellow color and streak with tabular subhedral crystals and good cleavage on {001}. It is transparent with vitreous luster and uneven fracture. Its density (calculated from the idealized formula) is 6.96 g/cm3. The mineral is monoclinic with the space group P2/c. Clearcreekite is an extremely rare mineral from the Clear Creek mercury mine, New Idria district, San Benito County, California. It was probably formed after the alteration of other mercury minerals such as cinnabar. The mineral is named after the locality where it was found.
Coloradoite, also known as mercury telluride (HgTe), is a rare telluride ore associated with metallic deposit. Gold usually occurs within tellurides, such as coloradoite, as a high-finess native metal.
Coccinite is a rare mercury iodide mineral with chemical formula of HgI2, mercury(II) iodide. It was first discovered in Casas Viejas, Mexico; it has also been reported from Broken Hill, New South Wales, and from a uranium mine in Thuringia and old mercury workings in the Rhineland-Palatinate in Germany. At the Thuringia deposit the mineral occurs as a sublimation product resulting from fires associated with pyrite-bearing graptolitic slate.
Christite is a mineral with the chemical formula TlHgAsS3. It is named after Dr. Charles L. Christ, a member of the U.S. Geological Survey. It usually comes in a crimson red or bright orange color. It has a density of 6.2 and has a rating between 1 and 2 on Mohs Hardness Scale. Christite has an adamantine luster and leaves behind an orange streak. Its crystal system is monoclinic with possible crystal classes of twofold symmetry, mirror plane symmetry, and twofold with a mirror plane. This means it can have radial symmetry, mirror plane symmetry, or mirror plane symmetry perpendicular to the two-fold axis. It is an anisotropic mineral, which means that it exhibits different properties when measured in different directions. In plane polarized light, its color is golden yellow. It is birefringent, which means that it has two distinct indices of refraction. This can be seen when one looks through the microscope with both polars crossed and sees the mineral change colors when it is rotated.
Metacinnabar is the cubic form of mercury sulfide (HgS). It is the high temperature form and trimorphous with cinnabar and the higher temperature hypercinnabar. It occurs with cinnabar in mercury deposits and is associated with native mercury, wurtzite, stibnite, marcasite, realgar, calcite, barite, chalcedony and hydrocarbons.
Edoylerite is a rare mercury containing mineral. Edoylerite was first discovered in 1961 by Edward H. Oyler, whom the mineral is named after, in a meter-sized boulder at the Clear Creek claim in San Benito County, California. The Clear Creek claim is located near the abandoned Clear Creek mercury mine. The material from the boulder underwent several analyses including, X-ray powder diffraction (XRD), a single crystal study, and a preliminary electron microprobe analysis (EMA). Using these analyses it was determined that this was a new mineral but the nature of the material at the time prevented further investigation. It was not until 1986, with the discovery of crystals large enough for a crystal structure determination and a sufficient quantity for a full mineralogical characterization, that the study was renewed. The new edoylerite crystals were found in the same area at the Clear Creek claim but were situated in an outcrop of silica-carbonate rock. This silica-carbonate rock was mineralized by cinnabar following the hydrothermal alteration of the serpentinite in the rock. Edoylerite is a primary alteration product of cinnabar. Though found with cinnabar, the crystals of edoylerite do not typically exceed 0.5mm in length. The ideal chemical formula for edoylerite is Hg32+Cr6+O4S2