Priceite
Priceite, also known as “Pandermite,” is a white, marble-like mineral. Although it is now called Priceite, it was once known as Pandermite after the Panderma area (now called Bandirma) of Turkey. The chemical formula of Priceite is Ca2B5O7(OH)5 · H2O and its molecular weight is 349.25 gm. The material from the Panderma area was thought to be a type of marble and was used for carving statues. One of these statues was analyzed by French amateur chemist Desmazures in 1865 and found to be high in boran. Priceite has a specific gravity of 2.42 (g/cm3) and the refractive index of 1.571 – 1.594 Biaxial ( + ). This “Pandermite” was later described as a new calcium borate mineral species, published in 1877, but by that time the mineral Priceite from California, USA had already been described four years previously. So the name Priceite has precedence even though Pandermite was known earlier.
There are a mumber of Priceite localities including: in the USA, from eight km north of Chetco, Curry County, Oregon; in California, from a number of occurrences around Death Valley, as the Monte Blanco area, in Corkscrew Wash, and the Furnace Creek district, Inyo County From the Penobsquis and Salt Springs evaporite deposits, near Sussex, New Brunswick, Canada. At Mesa del Almo, 13 km southeast of Magdalena, Sonora, Mexico. In Turkey, from the Sultan¸cayir borate deposit, Bursa Province, and in several deposits in the Bigadiç borate district, Balikesir Province. From the Inder borate deposit, Kazakhstan. At Meldon, Okehampton, Devon, England. From the Pöhla mine, Schwarzemberg, Saxony, Germany. At Radotin, Czech Republic.
| Chemical Formula: | Ca2B5O7(OH)5 · H2O |
| Molecular Weight: | 349.25 gm |
| Crystallography: | Monoclinic – Prismatic |
| Crystal Habit: | Crystals are platy with a rhombic outline, to 20 μm, aggregated in books; typically cryptocrystalline, nodular to massive. |
| Twinning: | None |
| Cleavage: | [001] Perfect |
| Fracture: | Conchoidal, Irregular/Uneven |
| Tenacity: | Tough to Friable |
| Hardness (Mohs): | 3.0 – 3.5 |
| Density: | 2.42 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Other: | Insoluble in water. Readily soluble in acids. Alters to Colemanite and Calcite. |
| Color: | White, Colorless in transmitted light. |
| Transparency: | Transparent to Translucent |
| Luster: | Porcelaneous to Earthy |
| Refractive Index: | 1.571 – 1.594 Biaxial ( + ) |
| Birefringence: | 0.0210 – 0.0220 |
| Dispersion: | Strong; r < v |
| Pleochroism: | None |
