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TOUBMAIiirrE. 341 Analyses of zircon a from Fried rich swam, I from the northern Circars by Klaproth, c from Ceylon by Vauquelin, d from Ex- pailly by Berzelius, e from North Carolina by Yanuxem, f zir con, o — 4*616, by Henneberg, q from Litchfield in Maine, G = 4*7, by G-ibbs:— a b c d e f g Silica 33 32*5 32*6 33*48 32*08 33*85 35*39 Zirconia .... 65 64*5 64*5 67*16 67*07 64*81 63*56 2*0 — — 1*55 0*79 — — — 0*88 — Red ox. of iron . . l 1*5 Lime In attached and imbedded crystals, especially in gneiss, granite and basaltic rocks, in matter ejected by volcanoes, in alluvium and in the sand of rivers, with other gems and with gold. Is found abundantly in syenite along the Christianiafjord from Staviirn to Ilackedalen in Norway, in the miascite of the Ilmen mountains, especially in the neighbourhood of lake Ilmen near Miask in Siberia, in granite or gneiss in New Jersey, New York, Sweden, Scalpay in the island of Harris, Ritiksut in Greenland, Meissen, in boulders of syenite at Assuan in Upper Egypt, on the Saualp in Carinthia in a bed of quartz, caleite and epidote in gneiss, in basalt at Unkel and the Sie- hengebirge on the Rhine, in basaltic conglomerate at Habichts- ^ald near Cassel; in amygdaloid at Expailly near Puy in I ranee, and at Vicenza in Italy, near the lake of Laach, and in pale blue crystals, which were first sent to this country as zeagonite, at the foot of Vesuvius in ejected volcanic rocks. In isolated crystals in alluvium in Ceylon and many other places in the East Indies, Expailly in France, at Zoblitz, Pod- wsdlitz and the Iserwiese in Bohemia, at Hohenstein and Sebnitz in Saxony, with gold in sand at Ohlapian and Muska In Transylvania, in the Ural and in Columbia. _ According to Svanberg the earth in zircon is composed of zirconia and noria in different proportions. Hence the varia tions of specific gravity and hardness in crystals of zircon from different localities. Zircon from Stockholm, for example, is not 8 o hard as zircon from other places, and its specific gravity ys only 4-03. Noria is supposed to occur principally, though not e xclusively, in zircon from Norway. 103. TOURMALINE.—Tourmaline; Phillips,Hauy. Rliom- opedriseher Turmalin ; Molis. Turmalin ; Hausmann, Hai- dinger. Rhombohedral. 100,111 = 27° 20'. Q 3