200 GRANITES AND GRANITIC VEIN-STONES. [XI. 



where large isolated crystals of white orthoclase, nearly color- 

 less muscovite, and brown tourmaline occur in a vein of vitre- 

 ous quartz. At Paris and at Hebron, Maine, tourmalines are 

 found penetrating crystals of quartz. The flattened tourma- 

 lines and garnets found in muscovite at several localities in 

 New England are well known to collectors, and a curious ex- 

 ample of enclosure has been observed by Professor Brush at 

 Hebron, where crystals of muscovite are encased in lepidolite. 



23. The following list includes the principal mineral 

 species found in these granitic veins in New England : apatite, 

 amblygonite, triphylline, autunite, yttrocerite, orthoclase, al- 

 bite, oligoclase, spodumene, iolite, muscovite, biotite, lepidolite, 

 cookeite, chlorite, chlorophyllite, garnet, epidote, tourmaline, 

 beryl, zircon, quartz, chrysoberyl, automolite, cassiterite, nitile, 

 brookite, uraninite, columbite, pyrochlore, scheelite, and bis- 

 muthine. As I am not aware that chlorite has hitherto been 

 mentioned as a constituent of these veins, it may be said that 

 it occurs in one at Albany, Maine. To the above should 

 be added the rare species nepheline, cancrinite, and sodalite, 

 which have long been known in bowlders of a granite-like rock 

 in Maine. According to information given me by Professor 

 Brush, green elaeolite with white orthoclase and black biotite 

 occurs in a granitic vein twenty feet in breadth, lately observed 

 in the northwest part of Litchfield, Maine. 



24. We have seen that these endogenous veins are found 

 alike in the gneisses, mica-schists, limestones, and quartzose 

 strata of this region. They are also met with in the eruptive 

 granites, small fissures in which are sometimes filled with 

 coarsely crystalline orthoclase, smoky quartz, various micas, and 

 zircon. Examples of this are seen in the granites of Hamp- 

 stead, New Brunswick, and Mount Uniacke, Nova Scotia. The 

 fine green feldspar of Cape Ann, Massachusetts, and the micas, 

 cryophyllite and lepidomelane, with zircon, described by Pro- 

 fessor Cooke, from the same region, occur in veins in the horn- 

 blendic granites of that locality. Small veins cutting a some- 

 what similar rock at Marblehead contain crystallized green 

 epidote with white quartz and red orthoclase. 



