J. E. Whitfield — Natural Borates and Borosilieates. 283 



These results prove the mineral to be the same as variety A, 

 but containing very slight impurities. The difference in gen- 

 eral appearance of the two specimens suggested a crystallo- 

 graphic examination of variety B, and the following descrip- 

 tion has been furnished by Mr. H. S. Washington of New 

 Haven. 



"The white transparent crystals, of about 2 to 5 mm in length, 

 occur implanted on a light porous gangue either in parallel posi- 

 tion or in rcsette-like aggregations, overlapping one another like 

 shingles on a roof. They have in several places implanted on 

 them small, white, opaque, spheroidal masses. The habit of the 

 crystals is remarkable, being unlike almost all the forms of cole- 

 manite previously described. Prof. A. W. Jackson* gives one 

 figure resembling these forms, though more complex. They look, 

 at first sight, like acute rhombohedrons of calcite ; the combi- 

 nation of prism and orthodome giving the mineral a decidedly 

 rhombohedral aspect, as is shown in the fig- 

 ure. None of the crystals examined admitted 

 of good measurement, the faces being broken, 

 rough, or curved. They were accurate enough 

 however, for determining the symbols. The 

 plane W 'was (30l) curved very conspic- 

 uously and regularly, the face having near a 

 (100) the position approximately represented 

 by the symbol 501. This habit was very con- 

 stant, the prism m, (110) and orthodome W 

 (301) being the only planes observed, with 

 the exception of b (010) produced by the perfect cleavage, and a 

 small and very uncertain plane observed in one or two cases 

 replacing the edge between W (301) and m' (no)." 



Priceite from Curry Co., Oregon. — The specimen examined 

 was white and chalky, and proved to be very pure material ; 

 an analysis gave the following composition, and I copy the 

 results of an analysis by Sillimanf and another by Mr. Thomas 

 Price:}: for comparison. 



H 2 ... 19-42 



B 2 3 48-44 



CaO 32-15 



NaCl, FeO„ Al O 



/ 



|\ 





/ 



K 





TK. 



mj 





Tri- 



mj 





\ 



•** N 





[ w' \ 





Silliman. 



Price. 



18-29 



22-75 



[4900] 



[47-04] 



31-83 



29-96 



•96 



•25 



100-01 100.08 100-00 



The ratios from my figures are CaO : B 2 3 : H 2 0— 19 : 23 : 36, 

 which do not conform to any simple formula. In both the 

 earlier analyses the boric acid was determined by difference 

 and there is a discrepancy between them of about 2 per cent. 



* Bull. Cal. Acad , No. 4. 



f Am. Jour. Sci., Ill, vi, 128. % Am. Jour. Sci., v, 287. 



