. Bulletin - New York State Museum. Science. in the direction of the orthoaxis producing forms of horizontal prismatic habit (fig. 227). These pass into acicular tonus, stri- ated in the direction of elongation, columnar, parallel or diver- gent, and fibrous masses (pi. 31J. It also occurs coarse to fine granular. The luster is vitreous, the crystals sharp and with bril- liantly reflecting faces; the color is com- monly some shade of pistachio-green, often nearly black, also yellowish green, gray or brown. Epidote occurs in metamorphic rocks of the older formations, in gneiss, mica and hornble
. Bulletin - New York State Museum. Science. in the direction of the orthoaxis producing forms of horizontal prismatic habit (fig. 227). These pass into acicular tonus, stri- ated in the direction of elongation, columnar, parallel or diver- gent, and fibrous masses (pi. 31J. It also occurs coarse to fine granular. The luster is vitreous, the crystals sharp and with bril- liantly reflecting faces; the color is com- monly some shade of pistachio-green, often nearly black, also yellowish green, gray or brown. Epidote occurs in metamorphic rocks of the older formations, in gneiss, mica and hornblende schists. It is found associated with quartz, the feldspars, actinolite and minerals of the chlorite group. It is common in Xew England and in many of the west ern states. Handsome specimens have been found in Orange and Putnam counties, X. Y. Axinite H,Cai(B0)Al,(Si04)r,( ?) Axinite is an aluminium and calcium borosilicate with some of the calcium replaced by iron and manganese. It occurs in sharp triclinic crystals with acute edges (fig. 228), clove-brown, bluish or yellow in color and in lamellar and curved lamellar masses. The luster is highly Prehnite H,Ca,Al,(SiQ.,).. Prehnite is an acid calcium and aluminium mi hosilicate. It is rarely found in isolated ort horhoiubic crystals of tabular habit but usually occurs in aggregates of such crystals united by their basal planes and producing barrellike, sheaflike and botryoidal shapes (pi. 31,) with crystalline surfaces. The luster is vitreOUS, faint pearly on the basal planes; the color is light green to oil green, yellowish green, graj i while. Prehnite occurs as a secondary mineral in veins and cavities in basic eruptive rocks, basalt, diabase, etc. also in gneiss anil granite associated with calcite, pectolite, datolite and the /.eo lites. It is sometimes associated with the copper of the Lake Superior region. Beautiful specimens are found in the neigh- borhood of Bergen TTill and Paterson X. -I. It is occasio
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
