Published online by Cambridge University Press: 01 July 2024
The present paper describes a new mineral species, namely a regularly interstratified chlorite —trioctahedral smectite bearing as much as 24% NiO. The high Ni content proves it to be nickel mineral.
On the diffractogram of the raw sample, an integral series of reflections with l.d(001) = 30·1 Å was obtained. To study the nature of the component layers, X-ray examinations of glycerol saturated samples and also dehydrated by heating were accomplished. Thermal and chemical analyses were performed in the usual way.
The crystallochemical formula can be presented as follows: saponite layer—(Mg,Ni)3·00 (Si3·75Al0·25) O10(OH)2, charge −0·25; Ca0·06 (Mg,Ni)0·06 K0·01, 4·07 H2O, charge +0·25; chlorite layer—(Mg, Ni)2·02(Al,Fe*)0·65(Si3·76Al0·24) O10(OH)2, charge −0·25; (Mg,Ni)2·75 (Al,Fe3+)0.25 (OH)6, charge +0.25.
The full mineral and chemical characteristics lead to precise conclusions concerning the composition and structure not only of the nonexpanding chlorite layers, but especially of the expanding layers. The latter show the chemical composition of saponite but the interlayer material is composed partly of exchange cations and molecular water and partly of “brucite-like pillows”.