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Kaolin
Sign in to saveAlso known as porcelain clay, china clay, kaolinite clay, paper clay, lithomarge, lithomarga, kao-lin, gaoling
clay rich in kaolinite
Key facts
- Category
- Phyllosilicate minerals
- Group
- Kaolinite- Serpentine group, kaolinite subgroup
- Formula
- Al 2 Si 2 O 5 (OH) 4 , or in oxide notation: Al 2 O 3 · 2SiO 2 · 2H 2 O
- Ima symbol
- Kln
- Strunz classification
- 9.ED.05
- Crystal system
- Triclinic
- Crystal class
- Pedial (1) , (same H-M symbol )
- Space group
- P 1
- Unit cell
- a = 5.13 Å , b = 8.89 Å , c = 7.25 Å; α = 90° , β = 104.5°, γ = 89.8°; Z = 2
- Color
- White to cream, sometimes red, blue or brown tints from impurities and pale-yellow; also often stained various hues, tans and browns being common.
- Crystal habit
- Rarely as crystals, thin plates or stacked. More commonly as microscopic pseudohexagonal plates and clusters of plates, aggregated into compact, claylike masses.
- Cleavage
- Perfect on {001}
- Tenacity
- Flexible but inelastic
- Mohs scale hardness
- 2–2.5
- Luster
- Pearly to dull earthy
- Streak
- White
- Specific gravity
- 2.16–2.68
- Optical properties
- Biaxial (–)
via Wikipedia infobox
Wikidata facts
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- Commons category
- Kaolin
Sources (2)
via Wikidata · CC0