KINDS OF ROCKS. 449 
II. SAUSSURITE-BEARING. 
6. Euphotide. (Gaddro in part.)—A grayish-white to gray- 
ish-green, and sometimes olive-green rock, very tough, haying 
G.=2°9-8°4. Consists of saussurite of whitish to greenish 
and bluish color, mixed either with smaragdite of emerald- 
green color, or with green to grayish-green diallage; the 
diallage gcnerally containing more or Jess hornblende, and 
the smaragdite, pyroxene. The saussurite is commonly of 
either the firsé or second kind mentioned on page 410; but 
the distribution of these kinds is not fully made out. Labra- 
dorite is rarely present locally in place of the saussurite. 
Metamorphie. 
VARIETIES.—a. Diallagic ; diallage the chief foliated mineral. b. 
Smaragditic ; emerald-green smaragdite, the foliated mineral. ec. Mi- 
caceous ; contains mica. d. Serpentinous ; contains some serpentine— 
a rock into which it often graduates. e. Garnetiferous. f. schistose ; 
especially so when tale is present. g. Variolitic ; contains aphani- 
tic concretionary spheroids of the saussurite mineral, asin the ‘‘ Vario- 
lite de la Durance,” and of Mt. Genévre, and asociated with ordinary 
euphotide ; for which concretions Delesse obtained the composition 
Silica 56°12, alumina 17°40, chromium oxide 0°51, iron protoxide 7°79, 
magnesia 3°41, lime 8°74, soda 3°72, potash 0°24, ignition 1°93 —99°85, 
and the specific gravity 2°923. The variety obtained at Orezza is the 
Verde di Vorsica, of decorative art. 
Occurs near Lake Geneva, in Savoy ; at Mt. Genévre in Daunohiny, 
near the boundary between France and Italy ; at Allevard, in the 
northeastern part of Isére ; in the valley of the Saas, north of east of 
the Monte Rosa region ; in the Grisons ; near Leghorn and Bologna ; 
near Florence, at Mt. Impruneta, it being the Granitone (page 450) 
of the Serpentine region ; on Corsica, in the Orezza valley; in Silesia ; 
in I. of Unst. It is often associated with serpentine ; and the serpen- 
tine and euphotide torm beds in irregular masses among, and as a 
constituent part of, a series of metamorphic strata, which include 
green chloritic and talcose schists, limestone (which, at Mt. Genévre, 
is of the Jurassic formation’, and other rocks. For the Mt. Genévre 
euphotide, Delesse obtained Silica 45-00, alumina and iron oxide 
26°85, lime 8-49, magnesia, soda and potash (by loss) 13°90, water 
and carbonic acid 6°78, anl for the saussurite the result stated on 
page 410. The composition is near that of a labradioryte, and the dif- 
ference in the two rocks must have depended on the different condi- 
tions attending crystallization. The mixture of hornblende and py- 
roxene in either foliated constituent, in connection with their mutual 
positions and structure, proves that part of the hornblende is altered 
pyroxene, ‘lhe remark made on page 410 with reference to the pro- 
duction of the saussurite may apply also to the foliated hornblende, 
and therefore to the whole rock. 
