MINERALS. 481 



crystals of it very frequently occur, and sometimes geniculated crystals or those bent like the knee. 

 Oxyd of Titanium is used for painting porcelain, and in giving a yellow color toartificial teeth. In Vermont 

 it has been found in Craftsbury, Middlesex, Waitsfield, Montpelier, Moretown, Bristol, Waterbury, 

 Corinth, Norwich, Rochester, Bethel, Marlboro, Dummerston, Putney and Newfane. It may be found 

 in the State Cabinet of minerals, under Nos. 99 to 101 inclusive. 



Ilmenite or Washingtonite (?) is a mineral of an iron-black color, with a little metallic luster and 

 crystallizing in rhombohedra of 86. Its chemical composition is peroxyd of iron, and peroxyd of 

 titanium. It is of no economic value as at present known. It occurs in Vermont, in Norwich and Troy. 

 It may be found in the Cabinet under the Nos. 76, 77, 78. 



Oariiet occurs in the primary form of a cube, although one of its most common secondary forms is the 

 dodecahedron. It has various shades of color, including red, brown, yellow, light-green and black. 

 Garnet is a silicate of different bases; alumina, lime, magnesia, oxyds of iron, manganese and chrome. 



The red garnet is used quite extensively as a gem, from its fiery red color and its hardness (being about 

 other the same as that of quartz.) In some superior collections of minerals it is made into vases and 

 ornamental work. When ground into powder, it is used as a substitute (adulteration ?) for emery. 

 This mineral occurs in Vermont, in the following towns : Halifax, Marlboro, Newfane, Grafton, Cavendish^ 

 Chester, Pomfret, Woodstock, Thetford, Charlotte and Peacham. It may be found in the State Collection 

 of minerals under the Nos. 241 to 253 inclusive. 



Pyrites, or Iron Pyrites as it is most commonly called, is a bisulphuret of iron. Its primary form is the 

 cube, although it has many modifications. In color it is a characteristic bronze-yellow, with splendent 

 luster. It is always very brittle and gives a spark when struck with steel, so that the name is derived 

 from the Greek which signifies "fire bearing." This is one of the commonest of minerals, occurring as it 

 does in nearly every formation, and is often mistaken for gold. It may always be distinguished from this 

 noble metal, however, by its hardness when scratched with the knife, or its ready crumbling under the 

 hammer. It also gives off a strong ordor of burning sulphur, when exposed to a strong heat. It is often 

 in globular masses, as well as simple crystals. Its economic uses are for making copperas, sulphuric acid, 

 as well as sulphur and alum. At Stratford, Vermont, it is an article of great value in making copperas, 

 as will be mentioned under economic geology. A few localities in Vermont are Alburgh, Fletcher, 

 Shoreham, Strafford, Vershire, Pomfret, Weathersfield, Hartford, Waterbury, Shrewsbury (formerly 

 worked), Arlington, Marlboro and Newfane. It can be seen in the State Collection under Nos. 40 to 

 50 inclusive. 



Pyroxene, of which Prof. Dana gives twenty-two varieties, and Prof. Shepard twenty-six, is a greenish- 

 colored mineral varying from grayish-white to black. In form it is referable to the monoclinic system of 

 Dana, and the oblique rhombic prism of Shepard. It is composed of the silicate of lime, magnesia, 

 protoxyd of iron, manganese or soda. This mineral is one of the most prominent ingredients of some of 

 the igneous rocks, including the recent lavas, and is generally the source of dark-colored metamorphic rocks 

 rocks. It is found in Vermont at the following localities : Newfane, Chester, Ripton (in bowlders) and Jay. 

 Its numbers in the State Collection are from No. 162 to 169 inclusive. 



Orthoclase, or Potash Feldspar, of which there are twenty-one varieties described by Prof. Dana, is one of 

 most common mineralogical constituents of primary rock. It is composed of silica, alumina and potash. 

 Its color is white, reddish-white, and sometimes green, with a vitreous luster, and often quite transparent. 

 Its form is probably referable to the oblique rhombic or rhomboidal prism. The principal economic value 

 of this mineral is the manufacture of pottery, it being the basis of all clays. Some of its best localities 

 in Vermont are Corinth, Strafford, Norwich, Chester, Newfane, and Saxton's River. Its numbers in the 

 Cabinet are from 271 to 275 inclusive. 



Quartz is one of the commonest of all minerals, and enters largely into the composition of nearly all 

 known rocks. Its primary form is that of the rhombohedron, though its most common mode of occurrence 

 is the hexagonal prism. Its chemical composition is nearly pure silica. The colors which.it assumes are 

 nearly all those of the rainbow. It occurs in crystals and masses which are perfectly transparent, and in 

 others which are absolutely opaque and black as jet. Some crystals have been found of very great size. 



