Transactions of The Royal Society of Canada 



SECTION IV 



Series III MAY, 1921 \ol. X\' 



Camsellite, a New Borate Mineral from British Columbia, Canada 



By H. W Ellsworth and E. Poitevin 



(Published by permission of the Deputy Minister of Mines) 



Presented by R. A. A. Johxsto.v. F.R.S.C. 



(Read May Meeting, 1921) 



Early this year (1921) Mr. W. Thomlinson, Collector in British 

 Columbia for the Department of Mines, sent in some specimens of a 

 fibrous vein material, asbestos-like in appearance, but characterized 

 by an almost pure white colour unusual in chrysotile. The specimens 

 were obtained from a serpentine mass near Douglas Lake in the 

 Nicola Mining Di\-ision, where the mineral is said to occur in con- 

 sideiable abundance filling shear zones in the serpentine. In heating 

 the white mineral before the blowpipe R. A. A. Johnston detected 

 the boron flame colour and further chemical examination confirmed 

 the presence of large amounts of BoOa. 



The samples so far examined are fragments of vein-like material 

 varying from one quarter inch to three inches in width and consist 

 of an intimate mixture of the new mineral with yellowish to greenish 

 chrysotile and white dolomite. There are no fibres crossing from 

 wall to wall as is commonly characteristic of chrysotile veins. The 

 trend of the fibrous structure is in a plane parallel to the extension 

 of the vein, though the fibres run in all directions within this plane, 

 giving the impression that many shearing movements have occurred 

 in various directions parallel to the veins. The vein material as a 

 whole, is also more or less crumpled and waxy and llie whole effect 

 is suggesti\'e of severe deformation. 



While the three minerals are all \ery intimaleh- associated so 

 that it has been impossible so far l(^ (jl)tain ihem individualK- pure 

 there are, nevertheless, layers \arying from a quarter of an inch in 

 thickness to paper thinness, in which one or other of the minerals 

 predominates. By selecting a layer of the white malerial which 



