| Loparite-(Ce) | |
| Category: | Oxide minerals |
| Imasymbol: | Lop-Ce[1] |
| Strunz: | 4.CC.35 |
| Color: | Black to grey-brown in thin section |
| Habit: | Cubic and octahedral crystals and massive |
| System: | Loparit-(Ce)-Q: tetragonal[2] Loparit-(Ce)-O: orthorhombisch Loparit-(Ce)-C: cubic[3] |
| Twinning: | Penetration twins common on [111] |
| Cleavage: | [100] Imperfect |
| Fracture: | Uneven |
| Tenacity: | Brittle |
| Mohs: | 5.5–6.0 |
| Luster: | Metallic to sub-metallic |
| Refractive: | n = 2.26–2.38 |
| Opticalprop: | Isotropic, anomalously anisotropic |
| Streak: | Reddish brown |
| Gravity: | 4.60–4.89 |
| Diaphaneity: | opaque, transparent in thin fragments |
| References: | [4] |
Loparite-(Ce) is a granular, brittle oxide mineral of the perovskite class. It is black to dark grey and may appear grey to white in reflected light on polished thin section with reddish brown internal reflections.[5] It has the chemical formula of .[4] Nioboloparite is a variation of loparite-(Ce) containing niobium.
Loparite occurs as a primary phase in nepheline syenite intrusions and pegmatites. It is also found replacing perovskite in carbonatites.[4]
Loparite was first described for an occurrence in the Khibiny and Lovozero massifs, Kola peninsula in northern Russia.
The term originates from the word Lopar, the (former) Russian name for the Sami indigenous inhabitants of the Kola peninsula, and the cerium content.[4] [5] [6]