Chromian Amesite
Chromian Amesite is a chromium (Cr) bearing a number of Amesite that is lavender that is coloured purple by the presence of the Chromium. Chromian Amesite is known as because of its chromium content and its own relationship to Amesite. Amesite ended up being named in 1876 by Charles Upham Shepard honouring James Tyler Ames (1810 – 1883), who had been an inventor that is us the part owner of the Chester Emery Mines in Massachusetts and had a rare and uncommon collection of minerals. A discover of Chromian Amesite in 2001 during the Saranovskii Mine, Urals Region, Russia produced extremely rich and colourful specimens with crystals to 4 mm and intense colours being purple. Although Amesite crystals are typically too small to be faceted, the Russian Chromian Amesite can be formed into breathtaking cabochon that is druzy-style covered in short, sparkling purple crystals as pictured above.
Chemical Formula: | Mg2Al(SiAl)O5(OH)4 + Cr |
Magnesium Aluminum Silicate Hydroxide + Chromium | |
Crystal System: | Triclinic |
Colour: | White, colorless, pink to lilac, pale green |
Hardness: | 2½ – 3 |
Lustre: | Resinous, Waxy, Greasy, Sub-Metallic |
Specific Gravity: | 2.77 – 2.78 |
Optical properties: | Biaxial (+) |
Transparency: | Transparent to translucent |
Tenacity: | Brittle |
Refractive index: | nα = 1.597 nβ = 1.599 nγ = 1.615 |
Cleavage: | Perfect on {001} |
Birefringence: | δ = 0.018 |