Elbaite
Elbaite, a sodium lithium aluminium boro-silicate mineral, is a known person in the Tourmaline band of minerals that also incorporates Dravite, Liddicoatite, Povondraite, Rossmanite, Schorl, Tsilaisite and Uvite. Even though the name Elbaite is not that well known, it is considered the most well known and type that is colorful of. Most gem Tourmalines are now actually Elbaite.
Elbaite is most likely the most type that is colorful of for sale in the gem market with gems of almost every color for the spectrum available. Some gems and crystals also contain two or more colors as with the really Watermelon that is popular Tourmaline. There are numerous gems available with combinations of two colors such as pink/colorless, red/green and blue/green. Achroite is a variety that is colorless of that is frequently, but not necessarily, Elbaite. Indicolite is the variety that is blue of. Rubellite is the pink to variety that is red of. Siberite is a rare variety of Elbaite that is lilac that is colored lavender, violet or violet-red to purple. Some of the other Elbaite varieties and colors are Verdelite (green), Paraiba (containing copper), yellow and orange.
Elbaite is also allochromatic, meaning trace quantities of impurities can tint the color of crystals. Elbaite can be meaning that is strongly pleochroic can happen to be different colors or hues when seen from different angles. Microscopic inclusions being acicular some Elbaite crystals show a pet’s eye effect in polished cabochons. Elbaite is additionally piezoelectric and pyroelectric and some specimens and gems may display weak bluish white to fluorescence that is blue shortwave UV light.
Elbaite, the range of Tourmaline, was named in 1913 by Russian mineralogist Vladimir Ivanovich Vernadsky (Vernadskii) (1863-1945) after its discovery locality on the island of Elba, Italy. However, the name Elbaite was initially given in 1883 by German mineralogist Carl Ludwig Giesecke (1761-1833) once the name of a mineral that is black turned out to be the mineral Ilvaite that has been described and named in 1811 by Norwegian naturalist Henrik Steffens (1773-1845). Steffens named Ilvaite after Ilva, the name that is ancient of area of Elba, where it absolutely was discovered. The name Ilva is through the title of the tribe that is ancient of Ilvate people who inhabited the island as early as 200 BC.
Elbaite distribution: numerous localities; some for exceptional specimens follow. In Italy, around San Piero in Campo, Elba. In the Yekaterinburg (Sverdlovsk) district, Ural Mountains, Russia. From Korgal and Mawi, Laghman Province, Afghanistan. In Pakistan, from around Gilgit and Stak Nala. At Ampantsikahitra, Anjanabonoina, Antandrokomby, Maharitra on Mt. Bity, and elsewhere on Madagascar. Into the Alto Ligonha district, Mozambique. At Karibib and Usakos, Namibia. In the USA, from Mt. Mica, near Paris, Newry, and somewhere else in Oxford County, Maine; at Haddam, Middlesex County, Connecticut; and from the Pala and Mesa Grande districts, San Diego County, Ca. In Brazil, from a district that is large Araçuaí-Itinga-Salinas, and the Itatiaia district, Governador Valadares, Minas Gerais; at São José da Batalha, Paraiba.
| Category: | Cyclosilicate |
| Chemical Formula: | Na(Al, Li)3Al6(BO3)3(Si6O18)(OH)4 |
| Sodium Lithium Aluminum Boro-Silicate Hydroxide | |
| Molecular Weight: | 916.68 gm |
| Elbaite Composition: | Sodium | 2.51 % | Na | 3.38 % | Na2O |
| Lithium | 1.89 % | Li | 4.07 % | Li2O | |
| Aluminum | 19.13 % | Al | 36.15 % | Al2O3 | |
| Silicon | 18.38 % | Si | 39.33 % | SiO2 | |
| Boron | 3.54 % | B | 11.39 % | B2O3 | |
| Hydrogen | 0.44 % | H | 3.93 % | H2O | |
| Oxygen | 54.11 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Trigonal – Ditrigonal Pyramidal |
| Crystal Habit: | Crystals prismatic to acicular, with prominent trigonal prism and pyramid, to 1.6 m, commonly hemimorphic, striated || [0001]. Also radial, fibrous, and massive. |
| Twinning: | Rare, on {1011} or {4041} |
| Cleavage: | Very poor on {1120}, {1011} |
| Fracture: | Irregular/uneven to conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 7.0 |
| Density: | 2.90 – 3.10 (g/cm3) |
| Luminescence: | Fluorescent; weak bluish white to blue under shortwave UV |
| Radioactivity: | Not Radioactive |
| Other: | Piezoelectric, Pyroelectric |
| Color: | Green, blue, red, orange, yellow, colourless, zoning common parallel to trigonal outline; colourless in thin section. |
| Transparency: | Transparent to Translucent |
| Luster: | Vitreous to Resinous |
| Refractive Index: | 1.615 – 1.651 Uniaxial ( – ) |
| Birefringence: | 0.0180 – 0.0200 |
| Dispersion: | n/a |
| Pleochroism: | Visible; O = pink, pale green, pale to deep blue; E = colorless, yellow, olive-green, purplish. |
