1897.] Mineralogy and Crystallography. 601 
General Notes, 
MINERALOGY AND CRYSTALLOGRAPHY? 
Lewisite and Zirkelite.—Hussak and Prior’ have given these 
names to two new Brazilian minerals. The lewisite, named in honor 
of Prof. W. J. Lewis, of Cambridge, Eng., was obtained from the 
cinnabar mine of Tripuhy in the gravel occurring on a hill-slope near 
Ouro Preto, Minas Geraes, Brazil. Xenotime, cinnabar, monazite, 
zircon, kyanite, tourmaline, rutile, hematite, pyrite, magnetite, gold, 
lewisite and a new titano-antimonate of iron, not yet obtained in quan- 
tity sufficient for accurate determination, constitute the heavy sand ob- 
tained by washing the gravel with a “ batea.” Lewisite occurs in per- 
fect honey-yellow to brown octahedra, seldom exceeding 1 mm. in 
diameter. Twinning on the plane 111 is rare. Translucent, isotropic, 
streak light yellow-brown, cleavage octahedral, hardness 5.5, lustre 
vitreous to resinous, specific gravity 4.95. A pulverulent sulphur- 
yellow decomposition product was sometimes observed on the surface 
and in cavities inside the crystals. The results of an analysis and the 
theoretical composition of 5 CaO, 3 Sb,O,, 2 TiO, are given as follows: 
Sb,0, 67.52 68.42 
iO, 11.3 11.70 
CaO 15.93 19.88 
FeO 4.55 
MnO 38 
Na,O 99 
100.72 100.00 
The lewisite is thus most closely related to Mauzeliite, an isometric 
inineral described by Sjögren (Geol. Féren. Férhand. Stockholm, 
XVII, pp. 313-318, 1895). Mauzeliite is brown, with Sp. G. 5.11, and 
gave, on analysis, Sb,O, 59.25, TiO, 7.93, PbO 6.79, FeO .79, MnO 
1.27, CaO 17.97, MgO .11, K,O .22, Na,O .27, H,O .87 and F 3.63 (by 
difference ?). The Swedish ainal contains much more lead and 
fluorine and less iron than that from Brazil. 
The name zirkelite is given to a black, isometric, nearly opaque 
titano-zirconate of calcium and iron which occurs in the form of octa- 
! Edited by Prof. A. C. Gill, Cornell University, Ithaca, N. Y. 
*Min. Mag., Vol. XI, Sept., 1895, pp. 80-88. 
42 
