Argutite
GeO2 [CNMNC approved formula]
Named for the occurrence in the Argut deposit, France.
| IMA status : | Approved Species 1983 (IMA1980-067) |
| CLASSIFICATION | |
| Dana (8th edition) : |
04.04.01.07 |
| (04) Simple Oxides | |
| (04.04) with a cation charge of 4+ (A++++ O2) | |
| (04.04.01) Rutile group (Tetragonal: P4/mnm) | |
| Nickel-Strunz (10th edition) : |
04.DB.05 |
| (04) Oxides and Hydroxides | |
| (04.D) Metal:Oxygen = 1:2 and similar | |
| (04.DB) With medium-sized cations; chains of edge-sharing octahedra | |
| Crystal system: | Tetragonal System |
| Point group (H-M): | 4/mmm (or 4/m 2/m 2/m) — ditetragonal-dipyramidal |
| Unit cell: | a = 4.398 Å, c = 2.863 Å |
| Crystal Habit: | Subhedral prismatic microscopic grains |
| Twinning: | occasionally twinned on {101} |
| Color: | Grayish black |
| Diaphaneity: | Semi-transparent |
| Luster: | Vitreous, adamantine |
| Hardness (Mohs): | 6 - 7 |
| Measured Density: | 6.28 (calculated) g/cm3 |
| Geologic Setting: | In a zinc deposit formed in metamorphosed lower Paleozoic sediments. |
| Mineral Association: | Sphalerite, cassiterite, siderite, briartite |
Sub microscopic grains of argutite invisible to the eye within sphalerite.Origin: Rimbatz, Argut-Dessus, Haute-Garonne, Midi-Pyrénées, France.
Sample size: 2.5 x 2 x 1.5 cm
Photo: Tom Loomis