Morganite (Beryl)
Morganite is the pink variety of the Beryl Family of minerals that also includes Aquamarine (blue), Bixbite (red), Emerald (green), Goshenite (colorless), Heliodor (yellow) and Pezzottaite (reddish pink). Morganite gets its pink-peach color from traces of manganese added to the basic Beryl formula. Like Aquamarine, large Morganite crystals have been found. Gems of several hundred carats have been cut from large crystals found in Brazil.
Morganite is known from several sources worldwide but the best sources of gemmy crystals are Konar and Laghman Provinces, Afghanistan; Minas Gerais, Southeast Region, Brazil; and in the USA at the Elizabeth R. Mine, Chief Mountain, Pala District, San Diego County, California, USA.
| Chemical Formula: | Be3Al2Si6O18 + Mn |
| Beryllium Aluminum Silicate + traces of Manganese | |
| Molecular Weight: | 521.21 gm |
| Composition: | Beryllium | 5.03 % | Be | 13.96 % | BeO |
| Aluminum | 10.04 % | Al | 18.97 % | Al2O3 | |
| Silicon | 31.35 % | Si | 67.07 % | SiO2 | |
| Oxygen | 53.58 % | O | |||
| 100.00 % | 100.00 % | = TOTAL OXIDE |
| Crystallography: | Hexagonal – Dihexagonal Dipyramidal |
| Crystal Habit: | Crystals prismatic to tabular; may be complexly terminated by pyramids. Also radial, columnar; granular to compact. |
| Twinning: | Rarely |
| Cleavage: | Imperfect/Fair on [0001] |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 7.5 – 8.0 |
| Density: | 2.71 – 2.90 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Various shades of Pink and peachy Pink |
| Transparency: | Transparent to Translucent |
| Luster: | Vitreous, Resinous |
| Refractive Index: | 1.572 – 1.600 Uniaxial ( – ) |
| Birefringence: | 0.008 – 0.009 |
| Dispersion: | 0.014 (low) |
| Pleochroism: | Weak to Distinct; O = colorless, E = pink |
