The natural Majorite with gem quality is the intermediate member of pyrope and almandine.
Basic Property of Majorite
- Its Composition is (Mg, Fe) 3Al2 [SiO4] 3
- Equiaxed crystal system.
- The density is 3.74 ～ 3.94g/cm3,
- The refractive index is 1.755 ～ 1.765.
Majorite is produced in North Carolina, Tanzania, Zimbabwe, Sri Lanka, Zambia, Brazil, etc. It is reported that starlight Majorite gemstones are also produced in East Africa.
The dispersion is 0.026, from pink to red, with good transparency, and the price is higher than that of almandine.
| Mineral name (Chinese) | 镁铁榴石 | Classification | Moonstone and meteorite minerals |
| Mineral name (English) | Majorite | code | 22019 |
| Chemical property | |||
| Crystal chemical formula | Mg3(Fe,Al,Si)2[SiO4]3 | ||
| Chemical composition | SiO2 54.89, | Al2O3 4.61, FeO 8.64, | MgO 30.99, CaO 1.63, Total 100.76 |
| Crystallographic characteristics | |||
| Crystal morphology | The crystal is micro granular, needle-shaped to equiaxed | with a particle size of 10 µ m, | produced in veinlet. |
| Crystal morphology Java image | Majorite [4/m [3] 2/m] | ||
| Crystal system | equiaxed crystal system | crystal class | hexaoctahedral crystal class |
| Symmetric type symbol | Oh-m3m(3L44L36L29PC) | space group | Oh10－Ia3d |
| Cell parameter a0 | 1.1524nm | Cell parameter α | 90° |
| Cell parameter b0 | 1.1524nm | Cell parameter β | 90° |
| Cell parameter c0 | 1.1524nm | Cell parameter γ | 90° |
| Cell parameter Z | 8 | ||
| X-ray powder diffraction | 2.575 (100*)， 2.881 (70)， 1.540 (60)， 2.454 (45*) | 1.597 (40)， 2.262 (35*)， 2.352 (30)*(similar to pyrope)： | (ICDD 25-843)-Due to goethite inclusion. |
| optical properties | |||
| Color: | purple, light yellow brown; Purple luster in the sheet | Gloss | |
| Transparency | Translucence | streak | |
| Polychromatic | dispersion | ||
| axial optical | homogeneity | Refractive | |
| mechanical property | |||
| Mohs hardness | 7-7.5 | relative density | 4 |
| Cleavage fracture | fracture | ||
| occurrence and associated minerals | |||
| occurrence | Under the high pressure of impact metamorphic phase of the fire meteor, pyroxene with low calcium and high aluminum, olivine, and shock wave-induced glass are formed. | ||
| Co associated minerals: | coarse pyroxene, spinel, olivine, kamacite, goethite |