THE MICA-APATITE DEPOSITS. 487 



6th. In quartz-felspar dikes cutting crystalline limestone, in which case 

 the crystals are generally of small size, mostly of dark color and of but 

 little value. 



In the case of the amber micas this peculiarity was noted that when 

 the pyroxene was of a light shade of green or greenish gra}^ and com- 

 paratively soft, the mica was correspondingly light colored and clear, 

 and in some places almost approached the muscovite in general appear- 

 ance. As the pyroxene became darker in color and harder in texture, 

 the mica assumed a correspondingly darker tint and a brittle or harder 

 character, and in certain cases where dikes of blackish hornblendic dio- 

 rite were present the mica also assumes a black color as well. 



Differences observable in the Mica-Apatite Deposits. — There is one feature 

 observed in the deposits of mica and apatite which is not yet explain- 

 able from the study of the rocks in the field. Thus in the apatite mines 

 along the Lievre river while the deposits of that mineral are sometimes 

 very extensive and can be traced downward for hundreds of feet, as 

 proved by the workings of the North Star and the High Rock mines, 

 the occurrence of mica in quantity with the apatite is rare, though in 

 certain areas both are present. In the Templeton or McGregor Lake 

 belt of apatite mines the two minerals frequently occur together, in 

 quantity sufficient to be profitably worked in both cases. Thus at the 

 Blackburn and Jackson Rae mines, the former especially long celebrated 

 for its great yield of apatite, the mica also occurs in considerable quantity 

 and in crystals of large size and good quality. In both the Lievre and 

 Tem[)leton areas the apatite is rarely found in cr3^stals, occurring for 

 the most part in pockety bunches which vary in size from insignificant 

 deposits to masses of a thousand tons. 



In the Gatineau area the quantity of pink calcite in the pyroxene 

 becomes much greater. There is very often an admixture of mica and 

 apatite crystals, the latter in quantity sometimes sufficient to be worken 

 profitably, while in other areas the mica occurs without the apatite 

 or with the latter only in ver}^ limited development. Very often quan- 

 tities of beautiful crystals of pyroxene, sphene and zircon, occur in 

 in these deposits with the mica. Of the apatite associated with the mica 

 in the Gatineau belt it may be said that it presents generally features 

 distinct from that occurring on the Lievre. The reasons for these dif- 

 ferent modes of occurrence and association are not, as already remarked, 

 very clear, unless it be due to some feature depending upon the strati- 

 graphical relations of the containing beds or some peculiarities regarding 

 their exact horizon. The diff'erence in the character of the micas them- 

 selves is presumably due to the difi*erence in composition of the con- 

 taining rocks. 



