74 MINERALS AND GEOLOGY 



Hemi-hexagonal, the crystals mostly acicular and very minute ; also 

 found in imbedded grains and small globular masses. H = 3.0, 

 3.5 (but not easily ascertained) ; sp. gr. 4.6 5.6. BB, melts into 

 a dark globule. One hundred parts contain ; Sulphur 35, Nickel 65. 

 Occurs very sparingly, in small specks, with calcspar and minute 

 green crystals of chrome garnet, in the Township of Orford (Lot 6, 

 Range 1 2), where it was first recognized by Dr. Sterry Hunt. 



19. Magnetic Pyrites (Pyrrhotino) . Bronze-yellow, with black 

 streak. Crystal-system, Hexagonal, but crystals very rare ; found 

 commonly in granular and irregular masses. H = 3.5 4.5 ; sp. 

 gr. 4.4 4.7. Slightly magnetic, many specimens exhibiting polar- 

 ity. The magnetism is best shewn by bringing a specimen of some 

 size near a suspended needle. As a general rule, a bar or horseshoe 

 magnet will only take up very small particles. BB, emits sulphur- 

 ous fumes, and melts into a dark slag-like mass. By roasting, becomes 

 veay easily converted into red oxide. Soluble in hot hydrochloric 

 acid, with emission of sulphuretted hydrogen odour. One hundred 

 parts yield, on an average, Sulphur 39.5, Iron 60.5 ; but many 

 varieties contain 3 or more per cent, of nickel, replacing part of 

 the iron. A variety from Madoc, (lot 10, con. 2), yielded the writer : 

 Sulphur 39.88, Iron 59.56, and contained no trace of cobalt, nickel, 

 or gold. 



Occurs in veins and irregular beds among the Laurentian strata 

 north of Thunder Bay, and in other localities a short distance inland 

 from the north shore of Lake Superior. Also, under similar con- 

 ditions, near Balsam Lake, <fec. ; and more or less throughout the 

 Laurentian district between Georgian Bay and the Ottawa. Like- 

 wise in a calcspar vein in Portneuf, Province of Quebec ; and still 

 more abundantly in St. Jerome, Terrebonne. Magnetic Pyrites occurs 

 also in the higher metamorphic district south of the St. Lawrence, 

 generally accompanying copper ores : as in the Townships of Barford, 

 St. Francis, and Sutton, and at the Ives and Huntington mines in 

 Bolton. 



20. Iron Pyrites (Cubical Pyrites, Mundic, &c.) : Pale brass-yellow 

 often brown on the surface from partial conversion into brown iron 

 oxide ; streak, greyish-black. Regular in crystallization, and fre- 

 quently found in cubes (usually with striated faces, the striae on one 

 face running at right angles to those on the adjacent face) ; also in 



