MAY, 1921. 
Canada 
Geological Survey 
Bulletin No. 32. 
GEOLOGICAL SERIES, No. 39. 
INYOITE FROM NEW BRUNSWICK. 
By Eugene Poitevin and H. V. Ellsworth. 
INTRODUCTION. 
During the course of a collecting trip in New Brunswick in the 
summer of 1916, A. T. McKinnon of the Geological Survey paid a visit 
to the Whitehead gypsum quarry, Hillsborough, Albert county, where there 
was brought to his notice a specimen which had attracted attention by 
reason of a beautiful arrangement of crystals covering one of its surfaces. 
The specimen is roughly a three-sided pyramid approximately 45 
centimetres in lerigth. Two of the basal edges measure approximately 22 
centimetres, the third edge about 16 centimetres. 
The most abundant mineral constituent of the specimen is a greyish- 
white, fairly compact, gypsum, but on the narrowest face of the pyramid 
there is an abundant crystal development which imparts to the specimen 
a very striking and handsome appearance. 
Its general aspect, as illustrated by Plates I and II, gives the impression 
that it represents a portion of the wall of a cavity or fissure of perhaps 
considerable dimensions. 
A more intimate examination of the specimen showed that in addition 
to the larger development of crystals on one surface groups of smaller 
crystals are to be found filling, wholly or in part, veinlets and vugs in other 
portions of the gypsum (Plate III). 
Some of the crystals having prismatic habit proved on examination to be 
selenite; the largest of these measured from 2 to centimetres in length 
by half a centimetre in thickness; some are simple individuals showing the 
combination of the chnopinacoid, the unit prism, the unit pyramid, and the 
negative orthodome e(103) ; in some cases twins were observed consisting 
of two individuals joined parallel with the orthopinacoid. The following 
forms have been observed: c(001), a(100), b(010), h(120), g(230), 5(350), 
f(110), 1(111), e(103). In general the prismatic faces show vertical stria- 
tions; these are particularly abundant on f (1 10) . 
Along with the selenite crystals, and sometimes superposed upon 
them, are numbers of white, translucent crystals which, as shown by 
physical and chemical examinations made by the authors, agree with 
the inyoite, described by Schaller, 1 from Death Valley, California. The 
occurrence now under consideration constitutes the second so far recorded 
for this species. 
1 U. s. Geol. Surv., Bull. 610, ser. 3, pp. 35-40. 
