Kornerupine
Kornerupine is a gemstone that is uncommon can be obtained in tones of green, bluish green, yellowish green and yellowish brown. The most gems that are desirable the emerald green gems from Sri Lanka and Tanzania that are colored green by the current presence of vanadium. Beautiful bluish green Kornerupine gems come from Madagascar and cats attention cabochons can be found from Sri Lanka. Star Kornerupine is discovered in Mogok, Myanmar (Burma) it is very rare. Kornerupine was initially found in Greenland as non-gemmy, radiating crystals but later found there as dark gemmy that is green.
Kornerupine was named in 1884 by Danish mineralogist Johannes Theodor Lorenzen (1855-1884) in honour of Danish geologist, Andreas Nikolaus Kornerup (1857-1883). Kornerup passed away at age 26 from the lung disease he contracted while on an expedition in Greenland. Although Kornerup died at such an age that is young he was able to establish himself being a well-respected geologist in Greenland research. Coincidentally, Johannes Lorenzen also died at an age that is young 29, while for an expedition in Greenland in 1884.
Current sources of treasure quality crystals are Ivohibe District, Horombe Region, Fianarantsoa Province, Madagascar; Mogok Township, Pyin-Oo-Lwin District, Mandalay Division, Burma (Myanmar); Matara District, Southern Province, Sri Lanka; Lelatema Mts, Simanjiro District, Manyara area, Tanzania.
Kornerupine circulation: some localities for well-studied material: In Greenland, at Fiskenæsset. At Bjordam, near Kragerö, Norway. In Germany, from Waldheim, Saxony. From Mautia Hill, Tanzania. In the Bok se Places Farm, Namaqualand, Cape Province, South Africa. Gem crystals from Itrongahy, near Betroka, and somewhere else in Madagascar. From treasure gravels of the Matale, Ratnapura, and Embilipitiya districts, Sri Lanka. In the Harts and Strangways Ranges, Northern Territory, Australia. At Lac Ste-Marie, Quebec, Canada.
| Category: | Borosilicates |
| Chemical Formula: | (Mg,Fe2+)4Al6(Si,Al,B)5O21(OH) |
| Magnesium Iron Aluminum Boro-silicate Hydroxide | |
| Molecular Weight: | 734.04 gm |
| Composition: | Sodium | 0.03 % | Na | 0.04 % | Na2O |
| Lithium | 0.04 % | Li | 0.08 % | Li2O | |
| Calcium | 0.05 % | Ca | 0.08 % | Ca2O | |
| Magnesium | 11.52 % | Mg | 19.11 % | MgO | |
| Titanium | 0.07 % | Ti | 0.11 % | TiO2 | |
| Aluminum | 24.48 % | Al | 46.26 % | Al2O3 | |
| Iron | 1.22 % | Fe | 1.57 % | FeO | |
| Silicon | 14.04 % | Si | 30.04 % | SiO2 | |
| Boron | 0.46 % | B | 1.47 % | B2O3 | |
| Hydrogen | 0.14 % | H | 1.21 % | H2O | |
| Oxygen | 47.93 % | O | |||
| Fluorine | 0.03 % | F | 0.03 % | F | |
| — | — % | F | -0.01 % | -O=F2 | |
| 100.00 % | 99.98 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals prismatic, to over 20 cm, rarely terminated; also as radiating aggregates and distinctly fibrous forms. |
| Twinning: | None |
| Cleavage: | Distinct on [110] |
| Fracture: | Irregular/uneven, conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 6.0 – 7.0 |
| Density: | 3.28 – 3.35 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Colorless, white, bluish green, green, dark green, greenish yellow, yellowish brown, black |
| Transparency: | Transparent to translucent and opaque |
| Luster: | Vitreous |
| Refractive Index: | 1.660 – 1.684 Biaxial ( – ); may be pseudouniaxial ( – ) |
| Birefringence: | 0.013 – 0.014 |
| Dispersion: | r > v or r < v; 0.018 |
| Pleochroism: | Distinct; X = colorless to green; Y = colorless, pale brownish yellow, pale yellowish green; Z = pale brownish green, green, light amber |
