Kaolinite

Kaolinite Crystallography

Composition

Al₂Si₂O₉H₄

Classification

1:1 Phyllosilicate, Kaolinite Group

Structural Parameters

a=5.1535 b=8.9419 c=7.3906 Å
alpha = 91.926, beta = 105.046, gamma = 89.797°
Space Group: C1

Atom	x/a	y/b	z/c
Al(1)	0.289	0.4966	0.466
Al(2)	0.793	0.3288	0.465
Si(1)	0.989	0.3395	0.0906
Si(2)	0.507	0.1665	0.0938
O(1)	0.049	0.3482	0.3168
O(2)	0.113	0.6599	0.3188
O(3)	0	0.5	0
O(4)	0.204	0.2291	0.030
O(5)	0.197	0.7641	0.001
OH(1)	0.050	0.9710	0.325
OH(2)	0.960	0.1658	0.607
OH(3)	0.037	0.4726	0.6046
OH(4)	0.038	0.8582	0.609
H(1)	0.145	0.0651	0.326
H(2)	0.063	0.1638	0.739
H(3)	0.036	0.5057	0.732
H(4)	0.534	0.3154	0.728

Atom

x/a

y/b

z/c

Al(1)

0.289

0.4966

0.466

Al(2)

0.793

0.3288

0.465

Si(1)

0.989

0.3395

0.0906

Si(2)

0.507

0.1665

0.0938

O(1)

0.049

0.3482

0.3168

O(2)

0.113

0.6599

0.3188

O(3)

0.5

O(4)

0.204

0.2291

0.030

O(5)

0.197

0.7641

0.001

OH(1)

0.050

0.9710

0.325

OH(2)

0.960

0.1658

0.607

OH(3)

0.037

0.4726

0.6046

OH(4)

0.038

0.8582

0.609

H(1)

0.145

0.0651

0.326

H(2)

0.063

0.1638

0.739

H(3)

0.036

0.5057

0.732

H(4)

0.534

0.3154

0.728

Reference:

Bish,DL. 1993. Rietveld refinement of the kaolinite structure at 1.5 K. Clays Clay Min. 41:738-744. [low defect, natural kaolinite; data above]

E. Akiba, H. Hayakawa, S. Hayashi, R. Miyawaki, S Tomura, Y Shibasaki, F. Izumi, H Asano, and T. Kamiyama. 1997. Structure refinement of synthetic deuterated kaolinite by Rietveld analysis using time-of-flight neutron powder diffraction data. Clays Clay Min. 45:781-788. [analysis of synthetic kaolinite prepared with deuterated water, differing primarily in placement of H(4)]