Ferrocolumbite
Columbite-(Fe) is a mineral that is rather common hardly ever available as a faceted gem mostly because it is opaque black to brownish black. However, it may be somewhat attractive with its vitreous to luster that is sub-metallic when its areas tarnish and become iredescent. Columbite-(Fe) is relatively hard with a Mohs hardness of 6.0 and very dense. It’s another of this gems which can be black enthusiasts associated with the unusual.
Columbite-(Fe) ended up being originally named Columbite (without the suffix that is-Fe in 1805 by Scottish naturalist and mineralogist Robert Jameson (1774-1854) because of its columbium content. The element columbium (Cb) was discovered and named in 1801 by English chemist Charles Hatchett (1765–1847) after Columbia, the historical and poetical title for America, where it absolutely was found that is first. The name Columbia was derived from, and honoring, Christopher Columbus, discoverer of America. Columbium was the initial, however now obsolete, name of the element niobium (Nb). Columbium was “rediscovered” in 1844 by German chemist Heinrich Rose (1795-1864) whom named it niobium from the Greek figure that is mythological, a daughter of Tantalus, additionally the Greek symbol of eternal mourning. The element columbium (Cb) was eventually assigned the real name niobium (Nb) in 1950 by the International Union of Pure and Applied Chemistry (IUPAC).
The mineral Columbite ended up being renamed Ferrocolumbite in 1844 by American mineralogist Charles Upham Shepard (1804-1886) for its iron that is ferrous) content. Ferrocolumbite ended up being sooner or later renamed Fe that is columbite the IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) in September, 2007 (proposal IMA 07-C) and published in an article titled “Tidying up Mineral Names: an IMA-CNMNC Scheme for Suffixes, Hyphens and Diacritical Marks” into the Mineralogical Record, vol. 39, No. 2, pages 131-135 (March – April, 2008).
A mineral with all the chemical that is exact same as Columbite was named Niobite in 1845 by Austrian mineralogist Wilhelm Karl Ritter von Haidinger (1795-1871) for its niobium (Nb) content. But the Columbite name had precedence that is historic remains to this day. Therefore, even though the title regarding the element which inspired the name Columbite had been changed from columbium to niobium, the mineral name continues to be Columbite and the name Niobite, that has been encouraged by the name that is current of element, had been abandoned. Go figure.
Distribution of Columbite-(Fe): in the USA, in Connecticut, at Middletown, Portland, and Haddam, Middlesex County; large masses from the Beecher Lode, eight km southeast of Custer, Custer County, and around Keystone, Pennington County, Southern Dakota; in the Spruce Pine district, Mitchell County, and also the Foote mine, Kings Mountain, Cleveland County, new york. At Ånneröd, Tveit, and elsewhere in Norway. In Russia, from Miass, Ilmen Mountains, Southern Ural Mountains. At Craveggia, Val Vigezzo, Piedmont, Italy. Large crystals from Ambatofotsikely and Antsirabe, Madagascar. At Greens Well, Wodgina, Greenbushes, and elsewhere in Western Australia. In the Ishikawa district, Fukushima Prefecture, Japan.
| Category: | Oxide minerals |
| Chemical Formula: | Fe2+Nb2O6 |
| Iron Niobium Oxide | |
| Molecular Weight: | 337.66 gm |
| Composition: | Niobium | 55.03 % | Nb | 78.72 % | Nb2O5 |
| Iron | 16.54 % | Fe | 21.28 % | FeO | |
| Oxygen | 28.43 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Orthorhombic – Dipyramidal |
| Crystal Habit: | Crystals short prismatic or equant, also flat tabular, to 0.75 m. In groups of parallel or subparallel crystals, to 18 t; massive. |
| Twinning: | Common as heart-shaped contact and penetration twins, on {021} and {023}, may produce pseudohexagonal trillings. More rarely on {051} and {15•1•0}. |
| Cleavage: | Distinct on {100}, less distinct on {010}. |
| Fracture: | Irregular/uneven, sub-conchoidal |
| Tenacity: | Brittle |
| Mohs Hardness: | 6.0; VHN = 652-739 (100 g load) |
| Density: | 5.20 – 6.65 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Paramagnetic |
| Color: | Black to brownish black. Reddish brown in transmitted light. |
| Transparency: | Opaque |
| Luster: | Vitreous, sub-metallic; commonly tarnishes to iridescent |
| Refractive Index: | Biaxial ( – ); R1–R2: (400) 18.4–19.1, (420) 17.7–18.6, (440) 17.3–18.2, (460) 17.1–17.9, (480) 16.9–17.7, (500) 16.9–17.6, (520) 16.8–17.5, (540) 16.8–17.4, (560) 16.7–17.3, (580) 16.7–17.2, (600) 16.7–17.2, (620) 16.6–17.1, (640) 16.5–17.1, (660) 16.4–16.9, (680) 16.3–16.8, (700) 16.1–16.8 |
| Birefringence: | 0.000 (opaque) |
| Dispersion: | r < v |
| Pleochroism: | None |
| Anisotrophism: | In reflected light: grayish white with a brownish tint and reddish internal reflections. |
