Ferro-Axinite
Axinite-(Fe) is a gem that is notably rare is generally intensely trichroic with brown and purple colors being dominant. Axinite-(Fe) is the iron analog of Axinite-(Mg) which may be the Magnesium analog. It’s difficult to get material without internal flaws and feathers. Inspite of the inclusions, Axinite is really a gem that is magnificent of its rich colors and brilliance.
There are many localities for Axinite-(Fe), even for fine crystals. On Roscommon Cliff as well as in the Botallack mine, St. Just, Cornwall, England. From Bourg d’Oisans, Isère, France. In the Maderantal, Uri, Switzerland. Extraordinary crystals through the Puiva deposit, about 100 km west-northwest of Saranpaul, Subpolar Ural Mountains; at Zlatoust, Ural Mountains; and elsewhere in Russia. At Skardu, Pakistan. In the Obira mine, Bungo, Oita Prefecture; the Toroku mine, Miyazaki Prefecture; and elsewhere in Japan. In the USA, from Coarse Gold, Madera County, near Yreka, Siskiyou County, and brand new Melones Lake, Calaveras County, Ca; and from Elkhorn, Jefferson County, Montana. In Canada, found near Hope, British Columbia, and within the Moneta mine, Timmins, Ontario. From Trinidad, Baja California, Mexico. At Vitoria da Conquista, Bahia, Brazil.
| Chemical Formula: | Ca2Fe2+Al2(BO3)Si4O12(OH) |
| Calcium Iron Aluminum Boron Sorosilicate Hydroxide | |
| Molecular Weight: | 570.12 gm |
| Composition: | Calcium | 14.06 % | Ca | 19.67 % | CaO |
| Aluminum | 9.47 % | Al | 17.88 % | Al2O3 | |
| Iron | 9.80 % | Fe | 12.60 % | FeO | |
| Silicon | 19.71 % | Si | 42.16 % | SiO2 | |
| Boron | 1.90 % | B | 6.11 % | B2O3 | |
| Hydrogen | 0.18 % | H | 1.58 % | H2O | |
| Oxygen | 44.90 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Cleavage: | Distinct on {100}, Poor on {001} and {110} |
| Fracture: | Irregular/Uneven to Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 6.5 – 7.0 |
| Density: | 3.25 – 3.28 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Brown, Purplish blue, Gray, Greenish yellow |
| Transparency: | Transparent to Subtransparent |
| Luster: | Vitreous (Glassy) |
| Refractive Index: | 1.672 – 1.701 Biaxial ( – ) |
| Birefringence: | 0.0090 – 0.0110 |
| Dispersion: | Strong, r < v |
| Pleochroism: | X = colorless, yellow, light brown, yellow brown, or pale green; Y = colorless, deep yellow, deep blue, pale violet, or violet; Z = colorless, pale green, olive yellow, brown, or dark violet |
