Mineraller ve özellikleri Alünit General Alunite Information Chemical Formula: KAl3(SO4)2(OH)6 Composition: Molecular Weight = 414.21 gm Potassium 9.44 % K 11.37 % K 2 O Aluminum 19.54 % Al 36.92 % Al 2 O 3 Hydrogen 1.46 % H 13.05 % H 2 O Sulfur 15.48 % S 38.66 % SO 3 Oxygen 54.08 % O ______ ______ 100.00 % 100.00 % = TOTAL OXIDE Empirical Formula: KAl 3(SO 4) 2(OH)6 Environment: Rock forming mineral where acid, often ore- bearing, solutions have altered orthoclase feldspar-rich rocks. Name Origin: From the Latin alunit, meaning "alum." Synonym: Aluminilite ICSD 12106 PDF 13-136 Alunite Crystallography Axial Ratios: a:c = 1:2.49354 Cell Dimensions: a = 6.97, c = 17.38, Z = 4; V = 731.22 Den(Calc)= 3.76 Crystal System: TrigonalSpace Group: R 3m, R 3m X Ray Diffraction: By Intensity(I/I o): 2.89(1), 2.99(1), 2.293(0.8), Forms: [ 0 1 2] [ 0 0 1] Physical Properties of Alunite Cleavage: [0001] Good Color: White, Gray, Yellowish gray, Reddish gray, Yellowish white. Density: 2.59 - 2.9, Average = 2.74 Diaphaniety: Transparent to translucent Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern. Habits: Massive - Granular - Common texture observed in granite and other igneous rock., Earthy - Dull, clay- like texture with no visible crystalline affinities, (e.g. howlite)., Fibrous - Cr ystals made up of fibers. Hardness: 3.5-4 - Copper Penny-Fluorite Luminescence: None. Luster: Vitreous - Pearly Streak: white Optical Properties of Alunite Optical Data: Uniaxial (+), w=1.572, e=1.592, bire=0.0200.