Hydroboracite
Hydroboracite is founded in 1834 in Atyrau Province, Kazakhstan. The Hydroboracite which comes in the category of Inoborates and formulae for hydroboracite is CaMgB6O8(OH)6·3H2O consisting of Calcium (Ca), Magnesium(Mg), and Borate. Hydroboracite is a borate that is uncommon much like Ulexite. It may be in Colorless or White. Another vital point of this stone is Virtually insoluble in cold water. Partially dissolved by prolonged submersion in boiling water. Every stone has a Crystal habit, for this As slender crystals, prismatic along [001] and flattened on {010}, to 10 cm; in fanlike to radial spherical aggregates and in swallowtail composites; as drusy coatings; compact, fine-grained. They both commonly form as silky, fibrous crystal clusters and are usually not easy to differentiate. Hydroboracite gems are particularly rare. Most crystals are silky and fibrous and never ideal for faceting. The Specific gravity of hydroboracite is 2.15 – 2.17 (g/cm3). The Optical properties of this stone are Biaxial (+). The crystal structure of a material (the arrangement of atoms within a given type of crystal) can be described in terms of its unit cell, so the unit cell of this crystal is a = 11.76, b = 6.68 c = 8.23 [Å]; β = 102.59°; Z = 2 ; The most known occurrences of Hydroboracite are: Kohnstein Quarry, Niedersachswerfen, Nordhausen, Harz Mts, Thuringia, Germany; Bigadiç Mine, Bigadiç, Balikesir Province, Marmara area, Turkey; Boron Pit, U.S. Borax Mine, Boron, Kramer District, Kern County, Ca, USA; and Death Valley, San Bernardino County, Ca, USA.
| Category: | Inoborates |
| Formula: | CaMgB6O8(OH)6·3H2O |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | As slender crystals, prismatic along [001] and flattened on {010}, to 10 cm; in fanlike to radial spherical aggregates and in swallowtail composites; as drusy coatings; compact, fine-grained. |
| Twinning: | None |
| Cleavage: | [010] Perfect, [100] Distinct |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Hardness (Mohs): | 2.0 – 3.0; 5.0 – 6.0 in some specimens |
| Density: | 2.15 – 2.17 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Virtually insoluble in cold water. Partially dissolved by prolonged submersion in boiling water. |
| Color: | Colorless, White |
| Transparency: | Transparent to Translucent |
| Luster: | Vitreous; Silky if fibrous |
| Refractive Index: | 1.520 – 1.571 Biaxial ( + ) |
| Birefringence: | 0.0490 |
| Dispersion: | Relatively Weak; r < v |
| Pleochroism: | None |
