1854.] On Nepaulite ; a New Mineral from Katfanandoo. 171 



of this singular mine, which I shall afterwards describe ; though I 

 do not think we have yet got the largest sized veins or masses of 

 the ore, or all the products of the mine ; for I have one specimen 

 of blue copper ore, which, as well as the green carbonate, is traced 

 in some of the specimens. 



I now proceed to describe the ore itself and its analysis. 

 Examination oe Nepaulite. 

 Description. 



1. External Characters. — The matrix of the ore should be first 

 described. It is principally quartz of all varieties, from the clearest 

 translucent, to the dullest granular and milky kinds ; but all are 

 beautifully stained with the fine turquoise blue of the copper which 

 the ore contains ; and the matrix is again varied by nests and plates 

 and even layers of another bright fawn-red ore, which here and there 

 looks like a pale red sandstone or iron ore, but which is a silicate of 

 Cerium and Iron (Cerite ?) so that altogether it forms one of the 

 most beautiful and showy of mineral ores, and will, I doubt not, be 

 highly prized amongst collectors. Sometimes the red ore is absent, 

 but the siliceous matrix is almost always stained with some shade of 

 blue, and at times has minute mamillated crystals of the pure Azurite 

 (blue carbonate of Copper) on its surface. Here and there chlorite 

 and talcose schists, and felspar appear, but not in any quantity, 

 though the mine is probably situated in a formation of one or both 

 of these rocks. In picking carefully over every fragment of the 

 rubbish, which I never fail to examine closely, I found a small por- 

 tion of a third ore also, an ore of Cerium (Allanite ?) which will be 

 described in its place : I return now to the Nepaulite. 



The ore is massive without the remotest trace of crystallisation.* 

 It occurs in veins, mostly in quartz, from six-eighths to one-eighth 

 of an inch in thickness, or smaller ; we have indeed but one piece 

 of the thicker kind, and though the thin veins are tolerably pure, 

 the thicker ones have almost all mixtures of imbedded, or veinous, 

 or granular quartz, so that it is very difficult to procure a pure bit 



* The fused ore shows at times some of the hackly, semi-crystallised fracture 

 of bismuth ; though it is mostly granular ; but it is of a pure silvery white colour ; 

 rarely showing any approach to the yellow white of bismuth, but sometimes is a 

 little brassy from the copper. 



