[ Top ] [ Japanese ]

Alum-(K)

Year of discovery: 1875 (World), 1875 (Japan)

Locality list: 34 localities of alum-(K)

• KAl(SO₄)₂,12H₂O
• (K,Na)Al(SO₄)₂,12H₂O
• [K(H₂O)₆]⁺[Al(H₂O)₆]³⁺[(SO₄)₂]^4-

• Class: Alum group
• Class: Sulfate - Hydrate
• Soluble in: Water
• Radioactive: Very weak
• Taste: Astringent
• Usage: Compress, Preservative, Color fixative, Sizing for paper production, Tanning

• K => Na: Alum-(Na)
• K => NH₄: Tschermigite
• K => Tl: Lanmuchangite

• Color: Colorless-White
• Streak: White
• Luster: Vitreous
• Diaphaneity: Transparent

• Cleavage: Indistinct on {111} (4 planes)
• Hardness: 2
• Density: 1.8

• System: Cubic
• Group: m3, Pa3
• Lattice: a=12.1