Arakiite
ZnMn2+12Fe3+2AsO3(AsO4)2(OH)23 [CNMNC approved formula]
Named for Dr. Takaharu Araki (1929-), University of Chicago, for his numerous crystal-structure contributions to the science of mineralogy.
| IMA status : | Approved Species 1998 (IMA1998-062) |
| CLASSIFICATION | |
| Dana (8th edition) : |
46.02.08.02 (This Dana# Added) |
| (46) Basic or Halogen-Containing Antimonites, Arsenites and Phosphites | |
| (46.02) with miscellaneous formulae | |
| (46.02.08) Dixenite Group | |
| Nickel-Strunz (10th edition) : |
08.BE.45 |
| (08) Phosphates, Arsenates, Vanadates | |
| (08.B) Phosphates, etc. with Additional Anions, without H2O | |
| (08.BE) With only medium-sized cations, (OH, etc.):RO4 > 2:1 | |
| Crystal system: | Monoclinic System |
| Point group (H-M): | m — domatic |
| Unit cell: | a = 14.248 Å, b = 8.228 Å, c = 24.23 Å, β = 93.62° |
| Crystal Habit: | Platy texture with "flexible" plates., Aggregates - Made of numerous individual crystals or clusters., Anhedral Grains - Granular minerals without the expression of crystal shapes |
| Color: | Reddish brown, orange brown |
| Diaphaneity: | Opaque to translucent |
| Luster: | Resinous - metallic |
| Hardness (Mohs): | 3 - 4 |
| Measured Density: | 3.4 (calculated) g/cm3 |
| Cleavage: | Perfect [001] |
| Tenacity: | Brittle |
| Fracture: | Uneven |
| Streak: | Pale brown |
| Geologic Setting: | As a component of stalactites and crusts on the walls of caves containing bat guano deposits. |
| Mineral Association: | Biphosphammite, aphthitalite, halite, syngenite, stercorite, oxammite, weddellite, whitlockite, guanine, newberyite, calcite, mundrabillaite |
| Other Properties: | H2O Soluble. |
Deep red massive arakiite between grains.Origin: Nordmark, Sweden.
Photo: © Rruff Project