Reidite
Reidite is an extremely rare mineral and gem. It is a high-pressure polymorph of Zircon with the Scheelite structure. Reidite has been found in an upper Eocene impact ejecta layer in marine sediments on the upper continental slope off New Jersey and Barbados and occurs in shock-metamorphosed Zircons. It is associated with impact glass (Tektites), shocked Quartz and Feldspar with multiple sets of planar deformation features, Coesite, and trace amounts of Stishovite. Reidite was first produced in high-pressure laboratory experiments in 1969 and has also been produced in shock recovery experiments.
| Category: | Zircon group |
| Formula: | ZrSiO4 |
| Zirconium silicate | |
| Crystallography: | Tetragonal – Dipyramidal |
| Crystal Habit: | Skeletal crystals up to 10 µm in length and 0.3 µm in width. |
| Twinning: | None |
| Cleavage: | None Observed |
| Fracture: | Irregular/Uneven |
| Tenacity: | Brittle |
| Hardness (Mohs): | 7.5 |
| Density: | 5.2 (g/cm3) |
| Luminescence: | None |
| Radioactivity: | Not Radioactive |
| Color: | Colorless, White |
| Transparency: | Transparent to Translucent |
| Luster: | Adamantine |
| Refractive Index: | 1.640 – 1.655 Uniaxial ( + ) |
| Birefringence: | 0.0150 |
| Dispersion: | n/a |
| Pleochroism: | None |
