Akimotoite
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| Akimotoite | |
|---|---|
| General | |
| Category | Oxide minerals Ilmenite group |
| Formula | (Mg,Fe)SiO3 |
| IMA symbol | Aki[1] |
| Strunz classification | 4.CB.05[2] |
| Crystal system | Trigonal |
| Crystal class | Rhombohedral (3) H-M symbol: (3) |
| Space group | R3 |
| Unit cell | a = 4.7284, c = 13.5591 [Å]; Z = 6 |
| Identification | |
| Color | Colorless |
| Cleavage | perfect (0001) |
| Luster | vitreous |
| Streak | white or colorless |
| Diaphaneity | Transparent |
| Specific gravity | 3.81(calculated) |
| References | [2][3] |
Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula (Mg,Fe)SiO3.[4] It is polymorphous with pyroxene and with bridgmanite, a natural silicate perovskite that is the most abundant mineral in Earth's silicate mantle.[2][5][6] Akimotoite has a vitreous luster, is colorless, and has a white or colorless streak. It crystallizes in the trigonal crystal system in space group R3. It is the silicon analogue of geikielite (MgTiO3).[2]
The crystal structure is similar to that of ilmenite (FeTiO3) with Si and Mg in regular octahedral coordination with oxygen. The Si and Mg octahedra align in discrete layers alternating up the c-axis. The space group is R3 (trigonal) with a = 4.7284 Å; c = 13.5591 Å; V = 262.94 Å3; Z = 6.[7]
