88 STRUCTURAL GEOLOGY. 



magnetite. A chrysolitic variety has been called nepheline-hasalt. Ash-gray to dark 

 gray. Often contains leucite, haiiynite, sanidin, etc. At Katzenbiickel ; Eifel, etc. 



Teschenyte. — Consists chiefly of anorthite or labradorite, nephelite, hornblende, 

 and augite. Felsitic in texture. The hornblende sometimes in large black jjrisins. Dark 

 bluish green. From Teschen, Silesia. 



m. Saussurite Rocks. 



EuPHOTiDE (Gabbro in part). — Grayish white to grayish green or olive green, and very 

 tough. Consists of saussurite, with diallage or smaragdite. G = 2 •9-3-4. A result of 

 the alteration of a labradorite and pyroxene or other related feldspar-bearing rock, in 

 which the feldspar is changed to the tough aphanitic mineral, saussurite (page 65). Cleav- 

 age of the feldspar sometimes retained, and found graduating into this feldspar in some 

 cases. Chrysolite often present ; and by its alteration, serpentine is sometimes abundant 

 in connection with it. Occurs near Lake Geneva in Savoy ; Mount Genevre in Dauphine ; 

 Corsica in the Orezza valley ; Isle of Unst, etc. 



IV. Rocks without Feldspar. 



1. Garnet, Epidote, and Tourmaline Rocks. 



Garnetyte {Garnet Bock). — Metamorphic. Massive, fine-grained. Yellowish or 

 buff to greenish white. Tough. G = 3 -3-3 -54. This rock is the much-used, pale, buff- 

 colored razor stone of Viel Salm, in Belgium, the best of stones for razors. It is a man- 

 ganesian garnet. It makes layers in a hydromica (sericite) schist. Occurs also as an 

 alumina-lime garnet at St. Francois and Orford in Canada. 



Eclogyte (Omphacyte). — Metamorphic. Fine-grained, granular. Consists of red 

 garnet in a base of grass-green smaragdite, with occasionally zoisite, actinolite, and mica. 

 Very tough. Also with black or greenish black hornblende and some magnetite. 



Epidosyte. — Metamorphic. Compact, and very tough and hard. Pale green to 

 yellowish green. Consists of epidote and quartz. A pale, yellowish variety from the 

 Shickshock Mountains, Gaspe. H = 7 and G = 3-3 -09. 



TouRMALYTE (Sckovl Bock) . — MetamorpMc. Consists of tourmaline and quartz, 

 with often chlorite and mica. Granular and compact to schistose. Occurs massive in 

 Cornwall, with tin ore ; schistose at Eibenstock in Saxony ; in Marble Mountains, and 

 Ragged Ridge, Warren County, N. J. 



2. Hornblende, Pyroxene, and Chrysolite Rocks. 



Pyroxeny'te. — Eruptive. Consists of black pyroxene. Coarse granular, or fine, 

 sometimes chrysolitic. Cortlandt, N.Y., and Stony Point, on the opposite side of the 

 Hudson. 



Picryte. — Eruptive. Consists of chrysolite, with pyroxene or diallage or hyper- 

 sthene. Blackish green, grayish to brownish red. Often partly changed to serpentine. 

 Graduates into chrysolitic basalt. From the Fichtelgebirge. 



Lherzolyte. — Eruptive. Consists of chrysolite, enstatite, whitish pyroxene, chrome- 

 spinel (picotite), and sometimes garnet. Changed more or less to serpentine. From 

 L. Lherz. 



HoRNBLENDYTE. — Eruptlve Or metamorphic-eruptive. Consists chiefly of hornblende 

 (which is generally altered augite) , with usually chrysolite. Massive or somewhat schis- 

 tose ; coarsely or finely crystalline. Cortlandt and Stony Creek, N.Y. 



HoRNBLENDE-picRYTE. — Usually Or always metamorphic-eruptive. Consists of horn- 

 blende (mostly or wholly altered augite) and chrysolite, with magnetite, the chrysolite 

 changed to serpentine ; usually more or less pyroxene. Coarse or fine crystalline granular. 

 Greenish black and dark gray. From Anglesey and Carnarvonshire. 



