kaolinite
| Kaolinite | |
|---|---|
 | |
| General | |
| Category | Phyllosilicates Kaolinite-serpentine group |
| Formula | Al2Si2O5(OH)4, or in oxide notation: Al2O3·2SiO2·2H2O |
| IMA symbol | Kln[1] |
| Strunz classification | 9.ED.05 |
| Crystal system | Triclinic |
| Crystal class | Pedial (1) (same H-M symbol) |
| Space group | P1 |
| Unit cell | a = 5.13 Å, b = 8.89 Å c = 7.25 Å; α = 90° β = 104.5°, γ = 89.8°; Z = 2 |
| Identification | |
| 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 (–) |
| Refractive index | nα = 1.553–1.565, nβ = 1.559–1.569, nγ = 1.569–1.570 |
| 2V angle | Measured: 24° to 50°, Calculated: 44° |
| References | [2][3][4] |
Főnév
kaolinite (tsz. kaolinites)