Rémondite
Rémondite is an extremely rare collector’s gem found only at Ebounja, near Kribi, Cameroon; Mont Saint-Hilaire, Quebec, Canada; and Kola Peninsula, Russia. The only gem quality crystals come from the Mont Saint-Hilaire location. Rémondite may show color change from pale greenish-yellow under daylight to pale orangish-yellow under incandescent light. Rémondite (Ce or La) may be weakly radioactive due to its Cerium and Lanthanum content.
| Formula: | Na3(Ce,La,Ca,Na,Sr)3(CO3)5 |
| Molecular Weight : | 611.79 gm |
| Composition: | Sodium | 11.65 % | Na | 15.70 % | Na2O |
| Lanthanum | 09.08 % | La | 10.65 % | La2O3 | |
| Cerium | 27.48 % | Ce | 32.19 % | Ce2O3 | |
| Strontium | 01.43 % | Sr | 01.69 % | SrO | |
| Calcium | 01.31 % | Ca | 01.83 % | CaO | |
| Carbon | 09.82 % | C | 35.97 % | CO2 | |
| Oxygen | 39.23 % | O | |||
| 100.00 % | 98.04 % | = TOTAL OXIDE |
| Crystallography: | Monoclinic – Sphenoidal |
| Crystal Habit: | Crystals, to 5 cm; massive, filling veinlets. |
| Cleavage: | Imperfect |
| Fracture: | Conchoidal |
| Tenacity: | Brittle |
| Moh’s Hardness: | 3.0 – 3.5 |
| Density: | 3.43 (g/cm3) |
| Radioactivity: | Weak; GRapi = 36,248.83 (Gamma Ray American Petroleum Institute Units) |
| Color: | Red-orange, amber-yellow; may show a color change between daylight and artificial light. |
| Transparency: | Transparent to Translucent (Transparent in thin splinters) |
| Luster: | Vitreous |
| Refractive Index: | 1.632 – 1.638 Biaxial ( + ) |
| Birefringence: | 0.0060 |
| Dispersion: | Weak to distinct |
| Pleochroism: | n/a |
