32 



TOPAZ GROUP. 



MAGNESIA GROUP. 



Periclase. 

 6io Brucite. — Thin layer on Serpentine. 



Log., Hoboken, New Jersey. 



6ii Do. White and foliated. 



Loc, Texas, Pennsylvania. 



Class V.-SILICATES, ALUMINATES, &c. 



SILICATE SECTION. 

 TOPAZ GROUP. 



612 Topaz. — Small colorless crystals, on granite. 

 Zoc, St. Michael's Mount. 



613 Do. Large colorless crystals, on granite. 



Loc, St. Michael's Mount. 



614 Do. Fine yellow crystals. 



Jjoc, Saxony. 



615 Do. Fine yellow crystal, on Quartz. 



Loc, Schneckensteine, near Auerbach. 



616 Do. Pale yellow crystals. 



Loc, Saxony. 



617 Do. Brownish-yellow crystals. 



Loc, Brazil. 



1 185 Do. Four rolled fragments. 



Loc, Beech worth, Victoria. 



Obs., Presented by Mr. Wm. Nicholas. 



618 Do. Pale yellow crystals. 



Loc, Saxony. 



619 Do. ib. Pyrophysalite.) — Massive. 



620 Do. {c. Fycniie.) — Deeply striated prisms, with Mica. 



Loo , Altenburg. 



