Sylvite Explained

Sylvite
Category:Halide mineral
Formula:KCl
Imasymbol:Syl[1]
Molweight:74.55 g/mol
Strunz:3.AA.20
System:Isometric
Class:Hexoctahedral (mm)
H-M symbol: (4/m 2/m)
Symmetry:Fm3m
Unit Cell:a = 6.2931 Å; Z = 4
Color:Colorless to white, pale gray, pale blue; may be yellowish redto red due to hematite inclusions
Habit:As cubes and octahedra; columnar, in crusts, coarse granular, massive
Cleavage:Perfect on [100], [010], [001]
Fracture:Uneven
Tenacity:Brittle to ductile
Mohs:2
Luster:Vitreous
Refractive:1.4903
Opticalprop:Isotropic
Pleochroism:Visible in colored crystals
Fluorescence:None
Streak:White
Gravity:1.993
Solubility:Soluble in water
Diaphaneity:Transparent to translucent
Other:Salty to bitter taste
References:[2] [3] [4]

Sylvite, or sylvine, is potassium chloride (KCl) in natural mineral form. It forms crystals in the isometric system very similar to normal rock salt, halite (NaCl). The two are, in fact, isomorphous.[5] Sylvite is colorless to white with shades of yellow and red due to inclusions. It has a Mohs hardness of 2.5 and a specific gravity of 1.99. It has a refractive index of 1.4903.[6] Sylvite has a salty taste with a distinct bitterness.

Sylvite is one of the last evaporite minerals to precipitate out of solution. As such, it is found only in very dry saline areas. Its principal use is as a potassium fertilizer.

Sylvite is found in many evaporite deposits worldwide. Massive bedded deposits occur in New Mexico and western Texas, and in Utah in the US, but the largest world source is in Saskatchewan, Canada. The vast deposits in Saskatchewan were formed by the evaporation of a Devonian seaway. Sylvite is the official mineral of Saskatchewan.

Sylvite was first described in 1832 at Mount Vesuvius near Napoli in Italy and named after historical KCl designations sal degistivum Sylvii and sal febrifugum Sylvii,[7] which are named after the Dutch physician and chemist François Sylvius de le Boe (1614–1672).[2]

Sylvite, along with quartz, fluorite and halite, is used for spectroscopic prisms and lenses.[8]

External links

Sylvite.

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. http://www.mindat.org/show.php?id=3850&ld=1&pho= Sylvite: Sylvite mineral information and data
  3. http://webmineral.com/data/Sylvite.shtml Sylvite Mineral Data
  4. http://rruff.geo.arizona.edu/doclib/hom/sylvite.pdf Handbook of Mineralogy
  5. Klein, Cornelis and Cornelius S. Hurlbut, Jr. 1993. Manual of Mineralogy after J.D. Dana, 21st edition. New York: John Wiley & Sons, Inc.
  6. Deer, W.A., R.A. Howie, and J. Zussman. 1992. An Introduction to the Rock-Forming Minerals 2nd ed. New York: Prentice Hall.
  7. Book: Watts, Henry . A Dictionary of Chemistry and the Allied Branches of Other Sciences . 1883 . Longmans, Green, and Company . en.
  8. Motz, Lloyd. Spectroscopy. Microsoft Encarta 2009. 2009. S. 1841.