130 



MINERALS AND GEOLOGY 



tine are placed first. To these, succeeds the hydrous sulphate, Gy] 

 sum ; and a few sapid types of obscure or comparatively rare occur- 

 rence, close the list.] 



97. Barytine or Heavy Spar : White, yellow, reddish, pale-blue, 

 grey, &c. Crystallization Rhombic (Figs. 77-78, and other combina- 

 tions). Occurs very commonly in lamellar masses and aggregations 

 of large flat crystals with cleavage angles of 101 40', 78 20\ and 90, 

 yielding a right rhombic prism. Also in masses of a granular or more 

 or less compact structure. H = 3.0 3.5 ; sp. gr. 4.3 4.7, mostly 

 about 4.4 4.5. BB, generally decrepitates, tinges the flame 

 pale-green, and melts with great difficulty, often at the point only, 

 into a white enamel. Dissolves entirely in carb-soda before the 

 blowpipe. Not attacked by acids. 

 Normal composition : sulphuric acid 

 34.33, baryta 65.67. This mineral 

 occurs abundantly in many parts of 

 Canada. In the Laurentian strata, FIG. 77. FIG. 78. 



it occurs in veins per se, and as a gangue or veinstone with galena 

 more especially in the townships of Lansdowne in Leeds County 

 Bathurst and North Burgess in Lanark County ; McNab, Renfrew 

 County ; Dummer and Galway, in Peterborough County ; and Som- 

 merville in Victoria County. A broad vein of white crystalline 

 heavy spar is exposed along the side of the road in lot 7 of the 10th 

 concession of Hull, near the Gatineau River. Red crystals were 

 discovered by Mr. Murray on Iron Island, Lake Nipissing ] and other 

 examples have been met with in the copper-ore veins of Lake Huron. 

 Isolated pale reddish-yellow crystals (Fig. 78) were found by the 

 writer (Canadian Journal, November, 1885,) in veins in Neebing 

 Township near Fort William, Thunder Bay, Lake Superior, and sub- 

 sequently in other mineral veins in that region. Massive and sub- 

 crystalline varieties from also large veins on Jarvis Island, near 

 Pigeon River west of Fort William, and also on Pie Island ; and 

 other veins of a similar character are said to occur east of Thunder 

 Cape, as at Edward Island in Black Bay, and elsewhere. Heavy Spar 

 has also been noticed in some of the serpentines and other altered 

 strata of the Eastern metauiorphic region south of the St. Lawrence, 

 as on the Bras River, where a white variety occurs in small veins. 

 Nodular masses of a red or reddish-yellow colour occur with fibrous 



