Geology and Mineralogy. 331 



the first and second order, the habit being the usual one for beryl, 

 and the specific gravity is 2*65. The color is presumably due 

 to manganese, of which the crystals contain a very appreciable 

 amount. Approximate chemical determinations leave no doubt 

 as to the identity of the species. The locality of occurrence is 

 that make known by the discovery of bixbyite, about 35 miles 

 southwest from Simpson Springs, Utah, in the Dugway Range. 

 The matrix is rhyolite, and the chief associates, according to Mr. 

 Bixbjr, are topaz, bixbyite and altered garnets. 



5. The Nickel and Copper Deposits of the Sudbury 3Iining 

 District, Ontario, Canada ; by Alfred Ernest Barlow. 236 

 pp., with 24 plates and five geological maps. From vol. xiv of 

 the Annual Report of the Geological Survey of Canada. Part 

 H. — The importance of the Sudbury mines will be appreciated 

 when it is stated that they now give Canada the position of the 

 largest producer of nickel in the world. This report by Mr. 

 Barlow is an admirable presentation of the whole subject, describ- 

 ing the geological relations and composition of the deposits, dis- 

 cussing their origin and also giving an account of the methods of 

 mining and metallurgical processes. A summary is also added of 

 the occurrence of nickel in other parts of the world, with particu- 

 lar reference to the Scandinavian deposits which in many respects 

 are strikingly similar to those of Canada. 



The nickel- and copper-bearing ore bodies consist essentially of 

 pyrrhotite, by far the predominant constituent, chalcopyrite in 

 much smaller amount and also pyrite. The nickel, however, is 

 almost entirely confined to the species pentlandite, which is in 

 general very uniformly distributed throughout the whole mass. 

 Both the pyrrhotite and pyrite carry nickel in small amount, but 

 it is not certain that it really belongs to the composition of these 

 minerals, some authorities referring it here also to admixed pent- 

 landite. Besides the species mentioned, the following nickel min- 

 erals also occur in limited amount : millerite, polydymite, niccol- 

 ite, gersdorffite and marcasite. Other associated species are the 

 following : morenosite, annabergite, sperrylite, danaite, smaltite, 

 galena, chalcocite, bornite, magnetite, cassiterite, native copper, 

 native gold, graphite, cubanite and some others. 



The deposits occur in connection with certain eruptive rocks. 

 These are discussed by the author under two divisions : 



(1 ) A basic portion : — Including certain gabbroid rocks, chiefly, 

 at least, of the norite facies, with their derivative diorites, with 

 which the nickel- and copper-bearing sulphides are immediately 

 associated. 



(2) An acidic portion : — Comprising large areas of rock of gran- 

 itic type, with well-marked gneissoid structure, the prevalence 

 and abundance of the graphic intergrowth of the quartz and feld- 

 spar, known as granophyre or micropegmatite, having suggested 

 the name " micropegmatite," by which this rock is now generally 

 known. 



The origin of the ore deposits is discussed in detail and the 

 author states his belief that the Sudbury deposits, like those of 



