36 Prof. How on the Mineralogy of Nova Scotia, 



ware*. In the case of silicoborocalcite the crystals may be found, 

 although it is best known in nodules ; indeed, as will be mentioned 

 immediately, it does sometimes appear crystalline. I carefully 

 examined a specimen of anhydrite and one of gypsum, not earthy, 

 holding the mineral, and detected in both a very small amount 

 of silica, perhaps some two- or three-tenths per cent. 



The small quantity of sulphuric acid recorded in the foregoing 

 analyses arises from the presence of a little selenite, which is 

 very frequently most intimately associated with the new mineral. 

 In the hard form in anhydrite thin bands of selenite are often 

 seen running through the nodules, which sometimes split so as 

 to leave a plate of it on the exposed surface. In gypsum the 

 nodules are sometimes distinctly banded with alternations of the 

 two minerals, and are often quite cellular, walls of selenite stand- 

 ing up between cavities retaining more or less borate. The sele- 

 nite sometimes carries Arragonite ; and this or calcite is occasion- 

 ally observed on the surface of the anhydritic matrix. Natro- 

 borocalcite occurs rather abundantly in an earthy gypsum hold- 

 ing the soft silicated borate, the minerals being independent 

 nodules ; and very well-marked coralloidal Arragonite or flos 

 ferri is occasionally found in cavities along with the borate in 

 gypsum : this newly observed fact is interesting, as it was in 

 gypsum of Arragon that Arragonite was first foundf. The 

 locality to which ±he preceding description refers is Brook- 

 ville, a property about three miles south of the Clifton quarry, 

 close to Windsor, where natroborocalcite was first observed. 

 Brookville is on the southern edge of the deposits of plaster 

 in this neighbourhood, and Clifton on the northern ; the depo- 

 sits extend east for more than forty miles ; and I have found 

 silicoborocalcite in a pure-looking gypsum from a quarry on 

 their range at Newport, about six miles to the east of Wind- 

 sor. Here it does not seem to be so abundant as at Brook- 

 ville; and it differs somewhat in external character, since it 

 is in white flattened nodules of a glistening crystalline appear- 

 ance, easily separable with a knife into rather gritty particles : 

 it is closely associated with selenite. I identified it by the 

 blowpipe -reactions and by qualitative analysis; the powder 

 stirred with cold hydrochloric acid gelatinized perfectly. 



New localities of Natroborocalcite. — Both Brookville and New- 

 port are new localities for this mineral, which has been men- 

 tioned as occurring at the former in the soft blue earthy gyp- 

 seous matrix of the silicated borate ; it is much the more abun- 

 dant of the two. It is in its characteristic nodules sometimes 



* Supplements to Dana's 'Mineralogy,' Silliman's Journal, May 1860 

 and May 1861. 



t Nicol's ' Mineralogy,' p. 296. 



