Constituent
- Name
- Kaolinite
- IMA name
- Kaolinite
- Class
- silicate mineral
- Compound type
- phyllosilicate
- Relevance
- main - minor
- Arrangement
- single phase
- Formula
- $Al_2.(Si_2O_5)(OH)_4$
- Chemical formula
- Al2Si2O5(OH)4
- Elemental formula
- Al2 Si2 O9 H4
- Isotope mixture type
- terrestrial abundance
- Composition comments
- Common impurities: Fe, Mg, Na, K, Ti, Ca, $H_2O$
- Oxides
-
Formula $Al_{2}O_{3}$ $SiO_{2}$ $H_{2}O$ Mass fraction (%) 39.5 46.55 13.96
Strunz
- Class
- silicates (09)
- Division
- phyllosilicate (09.E)
- Family
- Phyllosilicates with kaolinite layers (09.ED)
- Code
- 09.ED.05
Dana
- Major class
- silicates (VIII)
- Class
- phyllosilicate sheets of six-membered rings (71)
- Type
- with 1:1 layers (71.01)
- Group
- Kaolinite group (71.01.01)
- Code
- 71.01.01.02
- Phase type
- crystalline
- Crystal system
- triclinic
- Crystal class
- pedial
- Crystal class symbol
- 1 (C1)
- Crystal spacegroup
- P1
- Molar mass
- 258.16 $g/mol$
- Density
- 2.6 $g/cm^3$
- Refringence type
- biaxial
- Refringence sign
- negative
- Birefringence
- 0.007
- Refraction index $n_{\alpha}$
- 1.553 - 1.563
- Refraction index $n_{\beta}$
- 1.559 - 1.569
- Refraction index $n_{\gamma}$
- 1.560 - 1.570
- Dispersion V
- r > v weak
- Color
- white, brownish white, grayish white, yellowish white, grayish green
- Diaphaneity
- transparent to translucent
- Luster
- earthy