Apachite
Cu2+9Si10O29 • 11H2O [CNMNC approved formula]
Named for the Apache Indians, whose reservation is near the locality.
| IMA status : | Approved Species 1979 (IMA1979-022) |
| CLASSIFICATION | |
| Dana (8th edition) : |
78.04.01.01 |
| (78) Unclassified silicates | |
| (78.04) possible inosilicates | |
| (78.04.01) | |
| Nickel-Strunz (10th edition) : |
09.HE.10 |
| (09) Silicates | |
| (09.H) Unclassified Silicates | |
| (09.HE) With Cu, Zn | |
| Crystal system: | Monoclinic System |
| Point group (H-M): | Unknown — Unk |
| Unit cell: | a = 12.89 Å, b = 6.055 Å, c = 19.11 Å, b = 90.42° |
| Crystal Habit: | As minute, twisted or curved beaded spherules of radial ¯bers, composed of crystals; in seams, exhibiting a silky, fibrous structure on broken surfaces. |
| Color: | Blue |
| Diaphaneity: | Transparent to translucent |
| Luster: | Non-metallic, silky |
| Hardness (Mohs): | 2 |
| Measured Density: | 2.80 g/cm3 |
| Streak: | Light blue |
| Geologic Setting: | A retrograde metamorphic or mesogene mineral, formed at the expense of a prograde calc-silicate and sulfide assemblage in tactites; typically in fractures or crackled zones cutting garnet-diopside rock, replacing both these silicates and calcite. |
| Mineral Association: | Kinoite, gilalite, stringhamite, junitoite, clinohedrite, xonotlite, apophyllite, calcite, tobermorite |
Spherical crystals as singles to 0.2 mm and bunches in vuggy matrix.Origin: Christmas mine, Gila Co., Arizona, U.S.A. (type locality)
Sample size: 5 x 3 x 2.5 cm
Photo: Tom Loomis
(zoom-in of above)