PHYSIOGRAPHY. 169 



Rutile Sal- Ammoniac. 



3. It occurs, generally, in imbedded crystals, either in masses of 

 Quartz engaged in gneiss or mica-slate, or in Feldspar in chlorite-slate. 

 It is sometimes found massive in metalliferous veins, and is often enclo- 

 sed in crystals of Quartz : besides, it occurs in the shape of pebbles in 

 gome gold stream-works. 



4. Imbedded crystals in Quartz have been found at Rosenau in Hun- 

 gary, Teinach on the Bacher in Stiria, and at various places along the 

 chain of the Alps ; also at Crianlarich in Perthshire and other places in 

 Scotland. Very perfect crystals occur in the Saualpe, and massive va- 

 rieties at Arendal in Norway. Switzerland and Savoy afford several 

 localities. Pebbles have been found at Ohlapian in Transylvania which 

 on account of their dark color, have been called Nigrine. At St. Yrieix 

 in Fiance, and in the province of Guadalaxara in Spain, the well known 

 twin-crystals occur, often of very considerable dimensions. Finely crys- 

 tallized individuals are brought from St. Gothard, and beautiful capilla- 

 ry crystals engaged in transparent Quartz, from Brazil. 



The locality affording Rutile in the greatest quantity in the United 

 States, is a very extensive ledge of chlorife-slate at Windsor, (Mass.) 

 The crystals of Rutile are here thickly disseminated through narrow 

 vejns of Feldspar traversing this rock, and also occur in seams in the 

 rock itself. Large compound crystals of a dark color, occur at Monroe 

 and Huntington, (Conn.) rarely in the form of fig. 387. The mica- 

 slate of Hampshire, Berkshire and Fianklin counties, (Mass.) affords 

 this species, but no where, in any considerable quantity. It is found in 

 small brilliant crystals in white limestone with Spinel, Serpentine, Talc, 

 Mica, &c. at Amity, (N. Y.) and with blue Corundum, Tourmaline and 

 Spinel in the same rock at Newton, (N. J.) also in loose crystals in 

 North Carolina and Virginia. It is on the whole, one of the most wide- 

 ly diffused of the scarce metals, existing in small quantity at numerous 

 localities, but no where in the United States, excepting Windsor, in 

 abundance. 



SAHLITE. (See Pyroxene.) 



SAL-AMMONI AQ. Octahedral Ammoniac- 

 Salt. MOHS. 



Primary form. Regular octahedron. 

 Secondary forms. Cube. Trapezohedron. 



VOL. II. 15 



