| Cafetite | |
| Category: | oxide mineral |
| Formula: | · |
| Imasymbol: | Cft[1] |
| Strunz: | 4.FL.75 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/n |
| Unit Cell: | a = 4.944 Å, b = 12.109 Å, c = 15.911 Å; β= 98.93°; Z = 8 |
| Color: | Pale yellow to colorless |
| Cleavage: | Prismatic |
| Tenacity: | Brittle |
| Mohs: | 4–5 |
| Luster: | Adamantine |
| Refractive: | nα = 1.95, nβ = 2.08, nγ = 2.11 |
| Opticalprop: | Biaxial (–), 2V=58°, Dispersion very strong, r > v |
| Birefringence: | δ = 0.16 |
| 2V: | Measured: 38° |
| Pleochroism: | none |
| Streak: | White |
| Gravity: | 3.28 |
| Diaphaneity: | Semitransparent |
| References: | [2] |
Cafetite is a rare titanium oxide mineral with formula ·. It is named for its composition, Ca-Fe-Ti.
It was first described in 1959 for an occurrence in the Afrikanda Massif, Afrikanda, Kola Peninsula, Murmanskaja Oblast, Northern Region, Russia.[3] [4] It is also reported from the Khibiny and Kovdor massifs of the Kola Peninsula and from Meagher County, Montana, US.[3]
It occurs in pegmatites in a pyroxenite intrusion as crystals in miarolitic cavities. It occurs associated with ilmenite, titaniferous magnetite, titanite, anatase, perovskite, baddeleyite, phlogopite, clinochlore and kassite.[4]