Lazurite
Lazurite (Lapis Lazuli) is among the known members associated with the Feldspathoid team of minerals that features Cancrinite, Haüyne, Lazurite, Leucite, Nepheline, and Sodalite. Minerals with chemistries being close to those for the feldspars that are alkali but are poor in silica (SiO2) content are called Feldspathoids. Lazurite can also be a person in the group that is sodalite of that includes Hackmanite, Haüyne, and Tugtupite. Lazurite could be considered a sulphur form that is rich in. Lazurite crystals are seldom found, however. It really is more commonly discovered combined along with other minerals as a rock called Lapis Lazuli, or just Lapis. Lazurite and Lapis are two things that are separate Lazurite is a mineral and Lapis Lazuli is just a rock composed of many different minerals, but we have been grouping them together on this page as they are so closely related. Lapis contains mostly massive types of Lazurite coupled with Haüyne, Sodalite, Nosean, (all members of the group that is sodalite of) and white Calcite, Pyrite, as well as other minerals. The Calcite and Pyrite give Lapis a very appearance that is appealing the presence of Pyrite distinguishes Lapis from its blue cousin – Sodalite rock, which lacks Pyrite.
The name Lazurite is often confused with another mineral that is blue the phosphate mineral Lazulite. Although the names are similar, their habit that is crystal is different. Lazurite is very hardly ever found as distinct crystals and Luzulite has good crystal habit and luster that is vitreous. The mineral that is carbonate has a very similar color to Lazurite but is associated with the green carbonate mineral Malachite and reacts with acids. Lapis Lazuli has been mined for centuries from a source still in use today into the mountain that is remote of Kokcha, Afghanistan. Although there are other sources of Lapis worldwide, Afghanistan still produces the quality material that is finest.
| Category | Tectosilicate |
| Formula: | (Na,Ca)8 [ (S,Cl,SO4,OH)2| (Al6Si6O24) ] |
| Crystallography: | Isometric – Hextetrahedral |
| Crystal Habit: | In dodecahedra, or more rarely cubes, up to 5 cm; granular, disseminated, or massive. |
| Twinning: | None |
| Cleavage: | [110] Imperfect |
| Fracture: | Irregular, Uneven |
| Tenacity: | Brittle |
| Moh’s Hardness: | 5.5 |
| Density: | 2.38 – 2.42 (g/cm3) |
| Luminescence: | Fluorescent |
| Radioactivity: | Not Radioactive |
| Color: | Blue, Azure blue, Violet blue, Greenish blue |
| Transparency: | Translucent, Opaque |
| Luster: | Vitreous to Dull |
| Refractive Index: | 1.50 – 1.522 Isotropic |
| Birefringence: | 0.00 (Isotropic) |
| Dispersion: | 0.014 (low) |
| Pleochroism: | Distinct; purplish-red – orange-red |
| Anisotropism: | Anomalous |
