Chemistry:Quetzalcoatlite

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Quetzalcoatlite
Quetzalcoatlite-77801.jpg
Blue quetzalcoatlite on quartz from the Bambollita Mine (Oriental Mine), Moctezuma, Mun. de Moctezuma, Sonora, Mexico. Picture width 2 mm.
General
CategoryOxide mineral
Formula
(repeating unit)
Zn6Cu3(TeO6)2(OH)6·AgxPbyClx+2y
Strunz classification4.FE.45
Dana classification34.6.3.1
Crystal systemTrigonal
Crystal classHexagonal scalenohedral (3m)
H-M symbol: (3 2/m)
Space groupP3m1
Identification
ColorBlue, green in transmitted light
Crystal habitneedle-like hexagonal crystals, crystalline crusts, sprays
CleavageFair on {1010}
FractureBrittle
TenacityBrittle
Mohs scale hardness3
|re|er}}Pearly, dull
StreakPale blue, almost white
DiaphaneityTransparent
Specific gravity6.05 (measured)
Optical propertiesUniaxial (−)
Birefringenceδ = 0.062
Pleochroismblue-green
Ultraviolet fluorescenceNone
SolubilityInsoluble in water, soluble in cold HCl and cold HNO3. Decomposes in KOH when heated
References[1][2][3][4][5]

Quetzalcoatlite is a rare tellurium oxysalt mineral with the formula Zn6Cu3(TeO6)2(OH)6 · AgxPbyClx+2y. It also contains large amounts of silver- and lead(II)chloride with the formula AgxPbyClx+2y (x+y≤2).[2] It has a Mohs hardness of 3 and it crystallizes in the trigonal system. It has a deep blue color. It was named after Quetzalcoatl, the Aztec and Toltec god of the sea, alluding to its color.[3][4][5] It is not to be confused with tlalocite, which has a similar color and habit.

Occurrence

Quetzalcoatlite was first identified in the Bambollita mine (La Oriental), Moctezuma, Municipio de Moctezuma, Sonora, Mexico. It was later also found in another nearby mine, the Moctezuma mine, and it has also been found in mines in Arizona, Utah and California .[3] It occurs as a rare mineral in the oxidized zone of tellurium-bearing hydrothermal deposits and it is often associated with hessite, galena, bornite, cerussite, azurite, chlorargyrite, teineite, quartz, baryte, khinite, dugganite, and gold.[6]

References

External links