| Boleite | |
|---|---|
|   | |
| General | |
| Category | Halide mineral | 
| Formula | KPb26Ag9Cu24(OH)48Cl62 | 
| IMA symbol | Bol [1] | 
| Strunz classification | 3.DB.15 | 
| Crystal system | Isometric | 
| Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) | 
| Space group | Pm3m | 
| Unit cell | a = 15.29 Å; Z = 1 | 
| Identification | |
| Color | Deep Prussian blue to indigo | 
| Crystal habit | Cubic crystals | 
| Cleavage | [001] perfect | 
| Fracture | Uneven | 
| Mohs scale hardness | 3.0 – 3.5 | 
| Luster | Vitreous to pearly | 
| Streak | Greenish blue | 
| Diaphaneity | Translucent | 
| Specific gravity | 5.054 | 
| Optical properties | Isotropic | 
| Refractive index | n = 2.05 | 
| Other characteristics |  Radioactive 0.36% (K) | 
| References | [2] [3] [4] | 
Boleite is a complex halide mineral with formula: KPb26Ag9Cu24(OH)48Cl62. [3] It was first described in 1891 as an oxychloride mineral. It is an isometric mineral which forms in deep-blue cubes. There are numerous minerals related to boleite, such as pseudoboleite, cumengite, and diaboleite, and these all have the same complex crystal structure. [5] They all contain bright-blue cubic forms and are formed in altered zones of lead and copper deposits, produced during the reaction of chloride bearing solutions with primary sulfide minerals. [6]
The external property of a boleite crystal structure indicates its cubic structure. It is classified under the isometric crystal class. Boleite has a perfect cleavage in the [001] direction, and has a very dark glossy blue color with a light greenish-blue color streak. Twinning is best shown in this mineral by notches along the interpenetrated angles, which results in a crystal habit of pseudocubic penetration twinning along three different angles perpendicular to one another. Boleite has cubes over half an inch on each side, which consist of pseudo-octahedral tetragonal dipyramids. [7]
 
 Boleite was first collected as a very minor ore of silver, copper and lead at Boleo, Mexico. [6] Boleite was named after its place of discovery, El Boleo mine, on the Baja Peninsula, near Santa Rosalia, Mexico. [3]
Minerals associated with boleite include pseudoboleite, cumengeite, atacamite, anglesite, cerussite, phosgenite and gypsum at the type locality in Boleo, Mexico. In the Mammoth-St. Anthony mine of Arizona associated minerals include pseudoboleite, anglesite, cerussite, atacamite, paratacamite, leadhillite, paralaurionite, caledonite, phosgenite, matlockite and bideauxite. [2]