Clay mineral

Composition^b (wt%)

Amount of Ni^{2+ c}

Exchange rate (%)

BET SA^d

(m²・g⁻¹)

Na₂O

MgO

SiO₂

Fe₂O₃

NiO

Na⁺-mica

6.6

33.7

58.9

<0.1

<0.1

-

-

1.45

Ni²⁺-mica

1.8

34.3

59.2

<0.1

4.0

0.54

69

3.11