OF CENTRAL CANADA PART II. 95 



outer surface, arising from a deposition of numerous minute spots of 

 jasper or sesquioxide of iron. The colouring matter appears to con- 

 sist in certain cases of a minute trace of some silver compound. 



(d) Chalcedony : In nodular semi-tiarislucent masses of a yellow- 

 ish, grey, or reddish colour. Occasionally present in the amygdaloidal 

 traps of Lake Superior. Also in thin bands or veins, with Jasper, 

 on the River Ouelle in Kamouraska. The nodules pass more or less 

 into semi-opal. 



(e) Agate : In nodular masses of various clouded or banded 

 colours, either feebly translucent or opaque. Very abundant in the 

 amygdaloidal traps of St. Ignace, Agate Island, Michipicoten, etc., 

 on the north shore of Lake Superior, and in the shingle beaches of 

 these islands. Also in the conglomerates of Gaspe' ; and in the 

 pebbly beaches along the shores of Gaspe Bay, arising from the 

 destruction of these conglomerates. 



(f) Jasper : In opaque rounded masses, and in beds, of a brown, 

 red, green and other colour ; sometimes striped or banded ; and 

 always more or less dull or earthly-looking on the fractured surface. 

 Some remarkable quartz-rocks, evidently altered conglomerates, 

 containing pebbles of red Jasper, occur on the north-west shore of 

 Lake Huron. Many of the dark green and striped slates of Lake 

 Huron, also, may be regarded as closely akin to Jasper. At 

 Bachewahnung, on the east shore of Lake Superior, bands of red 

 Jasper are associated with hematitic iron ore ; and layers and 

 imbedded nodules occur in the copper-bearing series of the north 

 shore, around Thunder Bay, &c. Many of the so-called agates of 

 this region are properly Jaspers. Beds and layers of red Jasper, 

 in places very ferruginous, are found in the crystalline strata of 

 the Eastern Townships, as in Sherbrooke, Shipton, Broughton, &c., 

 and on the River Ouelle. Jasper pebbles are associated also with 

 agates in the conglomerates and Shingle beaches of Gaspe\ 



(g) Chert or Hornstone : Yellowish, brownish, reddish-white, 

 grey, black, &c. Mostly in nodular and irregularly-shaped masses, 

 and occasionally in beds and veins which often present a cellular 

 or brecciated structure. Translucent to nearly opaque. Closely 

 allied to Chalcedony and Flint. Occurs in the form of veins tra- 

 versing syenite in the township of Grenville, at first pointed out 

 by Sir William Logan. Also in layers, &c., in the upper copper- 



