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      K?mmererite Value, Price, and Jewelry Information

      By Didier Descouens (Own work) [CC-BY-3.0], via Wikimedia Commons

      K?mmererite

      K?mmererite is a beautiful but rare mineral. It is micaceous; consequently, it is extraordinarily difficult to facet, which has severely limited the availability of cut gems. It would have to be handled with great care to avoid cleaving. A few clean, well-cut gems do Perfect basal cleavage; micaceous; laminae exist, nonetheless, a testimony to the perseverance of hobbyists!

      K?mmererite Information

      Data Value
      Name K?mmererite
      Is a Variety of Clinochlore
      Colors Red to purplish red, cranberry red.
      Hardness 2-2.5
      Fracture Micaceous
      Cleavage Perfect basal cleavage
      Stone Sizes Facetable material is quite rare and always small. Minute gems, 1-2 carats, have been cut from Turkish material.
      Formula (Mg,Cr)6(AISi3)O10(OH)8. (Chlorite Group).
      Crystallography Monoclinic; crystals hexagonal shape, bounded by steep sided pyramids.
      Refractive Index 1.597-1.600
      Birefringence 0.003
      Luminescence None reported.
      Luminescence Present No
      Absorption Spectrum Not diagnostic.
      Pleochroism Strong; violet/hyacinth-red.
      Optics a?= 1.597; β = 1.598; γ = 1.599-1.600. Biaxial; optic sign variable.
      Optic Sign Biaxial +, Biaxial -
      Luster Vitreous; pearly on cleavages.
      Specific Gravity 2.64
      Transparency Translucent to transparent.

      Optics:? a?= 1.597; β = 1.598; γ = 1.599-1.600. Biaxial; optic sign variable.

      Occurrence: In chromite deposits, associated with clinochlore and uvarovite.

      Erzincan, Turkey: distinct crystals.

      Lake Itkul, near Miask, USSR.

      California; Texas: Pennsylvania.

      Comments: K?mmererite is a beautiful but rare mineral. It is micaceous; consequently, it is extraordinarily difficult to facet, which has severely limited the availability of cut gems. It would have to be handled with great care to avoid cleaving. A few clean, well-cut gems do Perfect basal cleavage; micaceous; laminae exist, nonetheless, a testimony to the perseverance of hobbyists!

      Name: After A. K?mmerer, the mining director at St. Petersburg.

       

       

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