32 



DESCEIPTIONS 



and numerous other localities, seem to authorize the adoption 

 of the opinion of De Witt Clinton, LL. D. Professor Nuttal, 

 and several Europeans, who prefer inclwling the granite and- 

 gneiss of Werner under the general name, granite. Varieties. 

 Sandy, at Liitle Falls. Porphyritic, in Johnstown, Mont- 

 gomery county, N. Y., Litchfield, Connecticut ; Chester, 

 Massachusetts. Graphic, in Litchfield, Conn, and South- 

 ampton mines. Contents. Steatite, in Savoy. DiaUage, Lake 

 George. Magnetic iron ore, Crown Point on Lake Cham- 

 Plumbago, pjjjijj^ Plumbago in beds almost co-extensive with the stratum. 



2. Mica-Slate, is an aggregate of grains of quartz and 

 scales of mica. Subdivisions. Compact, when tile slaty la* 

 minse are so closely united, that it will present an uniform 

 smooth face when cut transversely. Fissile, when the laminae 

 separate readily by a blow upon its surface. 



Localities. Compact, on the Boston stage road between 

 Worthington and Chesterfield, and between Shrewsbury and 

 Northborough, Massachusetts. Fissile, Fort Montgomery in 

 the Highlands ; Conway, Massachusetts. Contents. Stauro- 

 Plumbago, tide, Litchfield, and Goshen, Connecticut. Sappare, Ches- 

 terfield, Massachusetts ; Chatham, Connecticut. Garnet, ev- 

 ery where, and often plumbago. 

 Primitive 3. HoRNBLENDE RocK, is an aggregate, not basaltic, con- 

 rock and fel- sisting wholly, or in part, of hornblende and felspar. Subdi- 

 *par- visions. Granitic, when it presents the appearance of crys- 

 talline granite with hornblende subsituted for mica. Slaty, 

 when of a rifty or tubular structure. Varieties. Gneisseoid, 

 when it resembles slaty granite (gneiss) with scales of horn- 

 blende substituted for mica. Greenstone, when of a pretty 

 uniform green colour, and containing but a small proportion of 

 felspar, generally of a slaty structure. Porphyritic, when 

 spotted with cuboid blocks of felspar. Sienitic, when speck- 

 led with small irregular masses of felspar. 



Localities. Slate, east part of Becket, Mass., Butterhill, 

 in the Highlands. Granitic, Dalton, Mass., Highlands, ad- 



