Aluminum potassium sulfate
Aluminum potassium sulfate is a widely used ingredient in cosmetics, personal care, and skincare formulations. Depending on its function, it may serve as a moisturizer, preservative, emulsifier, or active ingredient to enhance the overall effectiveness and performance of a product.
Kalinite is a mineral composed of hydrated potassium aluminium sulfate (a type of alum). It is a fibrous monoclinic alum, distinct from isometric potassium alum, 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".
| Kalinite | |
|---|---|
 Kalinite from the Virgin Valley District, Nevada, USA. Specimen size 5.4 cm | |
| General | |
| Category | Sulfate minerals |
| Formula (repeating unit) | KAl(SO4)2·11H2O |
| IMA symbol | Kli |
| Strunz classification | 7.CC.15 |
| Dana classification | 29.5.4.2 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/c |
| Unit cell | a = 19.92(16), b = 9.27(3) c = 8.304(13) Å β = 98.79(19)°; Z = 4 |
| Identification | |
| Formula mass | 456.37 g/mol |
| Color | White to pale blue |
| Crystal habit | Fibrous |
| 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 | |
A proposal to remove recognition of kalinite as a mineral species was submitted to the International Mineralogical Association; however, kalinite is still on the list of approved minerals. Many older samples, however, have been found to be potassium alum.
