| Kalinite | |
|---|---|
Kalinite from the Virgin Valley District, Nevada, USA. Specimen size 5.4 cm |
|
| General | |
| Category | Sulfate minerals |
| Chemical formula | KAl(SO4)2·11H2O |
| Strunz classification | 07.CC.15 |
| Dana classification | 29.5.4.2 |
| Crystal symmetry | Monoclinic 2/m |
| Unit cell | a = 19.92(16) Å, b = 9.27(3) Å, c = 8.304(13) Å; β = 98.79(19)°; Z = 4 |
| Identification | |
| Molar mass | 456.37 g |
| Color | White to pale blue |
| Crystal habit | Fibrous |
| Crystal system | Monoclinic 2/m prismatic |
| Fracture | Conchoidal |
| Mohs scale hardness | 2 to 2.5 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 1.75 (observed) 2.0 (calculated) |
| Optical properties | Biaxial (-) |
| Refractive index | nα = 1.429 to 1.430, nβ = 1.452, nγ = 1.456 to 1.458 |
| Birefringence | None |
| 2V angle | 52° (measured), 82° (calculated) |
| Solubility | Soluble in water |
| Other characteristics | Not fluorescent, barely detectable radioactivity |
| References | [1][2][3][4] |
Kalinite is a fibrous monoclinic type of alum distinct from isometric potassium alum,[5] named in 1868.
Its name comes from Kalium (derived from Arabic: القَلْيَه al-qalyah “plant ashes”) which is the Latin name for potassium, hence its chemical symbol, "K".
A proposal to remove recognition of kalinite as a mineral species has been submitted to the International Mineralogical Association,[4] but it is currently (March 2010) on the list of approved minerals.[6] Many older samples, however, have been found to be potassium alum.[2]
Kalinite is a rare secondary mineral observed in the oxidized zone of mineral deposits, as efflorescence on alum slates, in caves, and as a volcanic sublimate.[7] It is associated with jarosite, KFe3+3(SO4)2(OH)6, and cuprian melanterite (pisanite), (Fe2+,Cu2+)SO4·7H2O, at Quetena, Chile.[8]