Kalinite

Kalinite
Kalinite from the Virgin Valley District, Nevada, USA. Specimen size 5.4 cm
General
Category	Sulfate minerals
Formula	KAl(SO4)2·11H2O
IMA symbol	Kli[1]
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	[2][3][4][5]

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,^[6] 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 was submitted to the International Mineralogical Association;^[5] however, kalinite is still on the list of approved minerals.^[7] Many older samples, however, have been found to be potassium alum.^[3]

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.^[8] It is associated with jarosite, KFe³⁺₃(SO₄)₂(OH)₆, and cuprian melanterite (pisanite), (Fe²⁺,Cu²⁺)SO₄·7H₂O, at Quetena, Chile.^[9]