450 DESCRIPTIONS OF ROCKS. 
6. PYROXENE AND SODA-LIME-FELDSPAR SERIES. 
1. Auzite-Andesyte—Contains the same triclinic feldspar 
as andesyte, but augite is present in place of hornblende. 
Amount of silica obtained in analyses about 55 to 58 per 
cent. Texture crystalline-granular to aphanitic ; colors dark 
gray to greenish-black and brownish-black. G.= 2°65-2:90. 
Hruptive. | 
VARIETIES.—There are two series: A. Ordinary, that is, without 
chrysolite, or only in traces. B. Chrysolitic, chrysolite being in 
disseminated grains or crystals. Under each there are varieties: 
a. anhydrous ; b. hydrous, or chloritic, and feeble in lustre; and 
c. amygdaloidal, as well as chloritic. Again, each of these varieties 
may be porphyritic. To the hydrous rock, and especially the chryso- 
litic, the term Melaphyre is sometimes applied. 
Quurtz-Augite-Andesyte is described by Zirkel as occurring in Pali- 
sade Canon, in Nevada Plateau ; it contains yellowish-brown augite, 
some biotite, some grains of quartz. Silica 62°71 per cent. 
2. Noryte. (Hyperyte, Hypersthenyte.)—A basic granitoid 
rock in part, consisting of cleavable labradorite with dis- 
seminated pyroxene, or a granular crystalline aggregate of 
the two minerals. The pyroxene is often foliated, and has 
been improperly called hypersthene. In place of labrador- 
ite, the feldspar is sometimes andesite, and sometimes anor- 
thite. Color, dull flesh-red to brownish-red, also dark-gray, 
to grayish-black. Tough. G.=2-7-3:1, varying with the 
proportion of pyroxene, which is sometimes small. Con- 
tains also magnetite or titanic iron. 
The name Gabbro has been applied to this rock; also to a coarsely 
granular igneous rock, consisting chiefly of labradorite and foliated 
pyroxene, referred beyond to doleryte; to euphotide; and, by the 
Halians, formerly to serpentine. Ferber, in his ‘‘ Briefe” (1773), says 
(p. 93): Gabbro of Florence is the same as the rock called ‘‘sichsi- 
schen Serpentin, in Deutschland,” that is, the serpentine cf Zéblitz. 
Again, on page 380. he says that Mt. Impruneta, seven [Italian miles 
from Florenes, consists of Gabbro, or the so-called Saxon serpentine, 
and he alludes to the occurrence in it of diallage and amianthus, and 
the presence also ‘‘ der sogenannte Granitone ” ‘‘ in horizontalen 
Schichten in den Gabbro-Bergen,” which sometimes consisted “aus 
weissem Feldspat, welcher grosse Parallelepipeden formirte,” though 
usually containing diallage. 
VARIETIES.—a. Granitoid ; the feldspar in distinct cleavable grains 
or masses. b. Heldspathose ; the pyroxene feeble in amount. c. Chry- 
solitic ; contains disseminated chrysolite. d. Anorthitic, or Tractolite ; 
anorthite replaces the labradorite. 
Noryte includes the so-called hypersthenite of the Adirondacks, Can- 
ada, and Norway. It occurs also in the Laramie Hills, Colorado, a 
