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Cahnite

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Cahnite
Cahnite on rhodonite
General
CategoryBorate minerals
Formula
(repeating unit)
Ca2B[AsO4](OH)4
IMA symbolCah[1]
Strunz classification6.AC.70
Crystal systemTetragonal
Crystal classDisphenoidal (4)
(same H-M symbol)
Space groupI4
Identification
ColorColorless to white
CleavagePerfect
On {110}
TenacityBrittle
Mohs scale hardness3
LusterVitreous
DiaphaneityTransparent
Density3.156 g/cm3
References[2]

Cahnite (Cahnit in German, Cahnita in Spanish, Канит in Russian[3]) is a brittle white or colorless mineral that has perfect cleavage and is usually transparent. It usually forms tetragonal-shaped crystals and it has a hardness of 3 mohs.[4][5] Cahnite was discovered in the year 1921.[3] It was named Cahnite to honor Lazard Cahn (1865–1940), who was a mineral collector and dealer.[4] It is usually found in the Franklin Mine, in Franklin, New Jersey,[5][4] but has also been found in Japan[6] as well as in the Vallerano quarries in Rome, Italy.[7] The geological environment that it occurs in is in pegmatites cutting a changed zinc orebody.[3][4][5] The chemical formula for cahnite is Ca2B[AsO4](OH)4.[5][8][9] It is made up of 26.91% calcium, 3.63% boron, 25.15% arsenic, 1.35% hydrogen, and 42.96% oxygen. It has a molecular weight of 297.91 grams.[5] Cahnite is not radioactive.[4] Cahnite is associated with these other minerals: willemite, rhodonite, pyrochroite, hedyphane, datolite, and baryte.[3]

References

[edit]
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mineralienatlas
  3. ^ a b c d Mindat data sheet for Cahnite.
  4. ^ a b c d e Mineral Data sheet for Cahnite.
  5. ^ a b c d e Database entry from Mineral Collecting.[permanent dead link]
  6. ^ Article stating that veins of cahnite were found in Okayama Prefecture. Archived 2012-02-17 at the Wayback Machine
  7. ^ "Cahnite". www.mindat.org. Retrieved 2022-06-26.
  8. ^ Database entry for Cahnite from Mincryst.
  9. ^ Database entry for Cahnite from Japanese database.