1883. | Mineralogy. 539 
Topaz FROM Mainr.—Mr. G. F. Kunz has discovered topaz in 
fine and large crystals at Stoneham, Maine. Some of the large 
opaque masses were parts of crystals measuring a foot across. Of 
transparent crystals one of a bluish and greenish tint measured 
2% inches vertically and three inches across. A number of in- 
teresting minerals are associated with the topaz. 
TURQUOISE FROM ARIZONA.—Professor W. P. Blake, in an inter- 
esting article in the American ¥ournal of Science for March, de- 
scribes some ancient mines of green turquoise in Cochise county, 
Arizona. The turquoise, which he has called “ chalchuite,’ from 
the aboriginal name of the gem, is of a light apple-green color 
like that from New Mexico, and has a specific gravity of 2.7-2.8. 
It occurs in rock in seams and veinlets rarely more than an eighth 
or a quarter of an inch in thickness. 
The locality is interesting from an archeological point of view. 
The mine had been worked probably by the Aztecs and Monte- 
zumas, and many ancient stone implements were found about the 
mine. Turquoise was in general use among the various tribes of 
a and was worked with considerable skill by ancient lapi- 
ries, 
Professor Blake thinks that turquoise should receive the min- 
eralogical name of either “cal/ainite,’ a modification of Pliny’s 
name “callaina,” or “chalchuite,’ derived from “chalchihuitl,” a 
name probably older than Pliny’s. 
MotyspenirE 1n Hone Konc.—F. Warrington Eastlake, in a 
communication to Mature, notes the occurrence of molybdenite 
or molybdenum glance (MoS,) on the island of Hong Kong. Sil- 
ver has been observed in small quantities, also galena, lead and 
Iron pyrites, 
The composition of the molybdenite is, sulphur 40 per cent, 
molybdenum 60 per cent, or one per cent less of sulphur than is 
ven by Dana as the composition of American molybdenite. 
WATER IN CHALCEDONY.—A geode of chalcedony recently re- 
ceived from Salto river Uruguay, contains an unusual amount 
SOME ENCLOSURES IN MuscoviTe.—Professor Lewis, in a paper 
read before the Philadelphia Academy, on Dec. 26, 1882, discusses 
‘Ae enclosures of biotite and magnetite so frequent in the musco- 
vite of Southern Pennsylvania and Northern Delaware. By dis- 
šecting a crystal of muscovite enclosing biotite into a consecutive 
Series of cleavage laminze, a vertical section of the crystal is ob- 
tained, which, as exhibited in an accompanying plate, shows that 
While the edges of both the outer and inner crystals remain_par- 
allel in successive plates, the substance of the black biotite 1s 
Stadually eaten away, and is replaced by the encroaching musco- 
