| Ammineite | |
| Category: | Chloride mineral |
| Formula: | CuCl2(NH3)2 |
| Imasymbol: | Amm[1] |
| System: | Orthorhombic |
| Class: | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Symmetry: | Cmcm |
| Unit Cell: | a = 7.79, b = 10.64 c = 5.84 [Å] (approximated) |
| Color: | Blue |
| Habit: | Hypidiomorphic crystals; powdery masses |
| Mohs: | 1 |
| Luster: | Vitreous |
| Streak: | Light blue |
| Gravity: | 2.38 (calculated) |
| Pleochroism: | Dark blue to light blue |
| References: | [2] [3] |
Ammineite is the first recognized mineral containing ammine groups. Its formula is [CuCl<sub>2</sub>(NH<sub>3</sub>)<sub>2</sub>]. The mineral is chemically pure. It was found in a guano deposit in Chile.[2] [3] At the same site other ammine-containing minerals were later found:[4] [5] [6] [7]
The characteristic features of the structure of ammineite are:[2]
Ammineite coexists with atacamite, darapskite, halite and salammoniac.[2]
Ammineite is supposed to be a result of an interaction of an earlier copper mineral, likely from a plutonic rock, with ammonia in guano. Ammonia may be produced in decomposition of compounds like urea or uric acid.[2]