Kleinite Explained

Kleinite
Formula:(Hg2N)(Cl,SO4) · nH2O
Strunz:3.DD.35
System:Hexagonal
Class:Dihexagonal dipyramidal 6/mmm (6/m 2/m 2/m)
Unit Cell:a = 6.762(2) Å, c = 11.068(3) Å, Z=4
Color:Light to canary-yellow, orange
Habit:Short prismatic to equant crystals exhibiting prominent,, and
Cleavage:Uneven on, imperfect on
Tenacity:Brittle
Mohs:3.5
Luster:Adamantine to greasy
Streak:Sulfur yellow
Diaphaneity:Transparent to translucent
Gravity:7.9-8.0
Opticalprop:Uniaxial (+) (Biaxial below 130 °C (biaxial negative) and uniaxial above 130 °C (uniaxial positive). Isotropic above ~ 190 °C)
Refractive:nω = 2.190 nε = 2.210
Birefringence:δ = 0.020
Other:Color deepens on exposure to daylight, original color returns in darkness
References:[1]

Kleinite is a rare mineral that has only been found in the United States and Germany that occurs in hydrothermal mercury deposits. It occurs associated with calcite, gypsum and (rarely) barite or calomel. Its color can range from pale yellow/canary yellow to orange, and it is transparent to translucent. As a photosensitive mineral, its coloration darkens when exposed to light.

It has been hypothesized that kleinite formed through a "reaction of cinnabar with oxidized meteoric water", with this reaction being the source of kleinite's nitrogen.

Etymology

Kleinite is named after Carl Klein (1842–1907), who was a professor of mineralogy at the University of Berlin.

See also

Notes and References

  1. https://www.mindat.org/min-2225.html Kleinite data on Mindat