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Kaolinite [abbr. Kln ]

Year of discovery: 1637 (Gaoling mine, China), 1901 (Japan)

Locality list: 1,178 localities of kaolinite

• Al₂Si₂O₅(OH)₄
• [Al³⁺₂][(OH)₄|Si₂O₅]^6-

• Class: Kaolinite subgroup < Serpentine-Kaolin group
• Class: Phyllosilicate - Hydroxide
• Polytypes are not recognized as independent mineral species, but clay minerals are exceptions.
• Formed at lower temperature than Dickite.
• Soluble in: HCl (Decompose)
• Magnetism: Diamagnetic
• Incrustation pseudomorph: Replace Scheelite.

• Polymorph: Halloysite-7Å (Monoclinic)

• Color: White, Pale brown
• Streak: White
• Luster: Waxy
• Diaphaneity: Translucent-Opaque

• Habit: Earthy, Hexagonal Platy

• Cleavage: Perfect on {001} (1 plane)
• Hardness: 2-2.5
• Density: 2.6

• System: Monoclinic (1Md, 2M₁, Dickite), Monoclinic (2M₂, Nacrite), Triclinic (A, Kaolinite) (Layer-stacking polytype)
• Group: 1, P1
• Lattice: a=5.1, b=8.9, c=7.3, α=90.0, β=104.5, γ=89.8

Etymology: Kauling village in Jiangxi, China