TJNISILICATES. 263 



Zoisite. A mineral of the epidote group, occurring in trimetric crys- 

 tals, with IaI— 116° 40', and having a white, pale-grayish, pale- 

 greenish to reddish color ; also massive. H.=6-6 5. G.=31-34. 



It is a lime-epidote, with little or no iron. B.B. swells up and 

 fuses to a white blebby glass ; after ignition, gelatinizes with hydro- 

 chloric acid. Thulite is a rose-red variety. Occurs at Saualpe in Carin- 

 thia, in the Tyrol ; Arendal, etc. ; in Vermont at Willsboro' and Mont- 

 pelier ; in Massachusetts, at Goshen, Chesterfield, etc. ; in Pennsyl- 

 vania at Unionville, and in Tennessee at the Ducktown copper mine. 



Saussurite, from the euphotide of the Alps in the vicinity of Lake 

 Geneva, approaches zoisite in composition, it affording Hunt Silica 

 43 "59, alumina 27*72, iron sequioxide 2'61, magnesia 2*98, lime 1971, 

 water 0-35, soda 3 08 = 100 04. Color whitish, greenish gray, ash-gray ; 

 G. = 3 226-3 '385. H. = 6 '5-7. The saussurite of Orezza gave nearly the 

 same composition in an analysis by Boulanger, and that of Schwartz, 

 wald in general the same, with more of magnesia and less of lime, in 

 an analysis by Hutlin. The high specific gravity separates it from 

 scapolite (wernerite) which it resembles in composition, and also from 

 the feldspar group. 



Jadeite, one of the kinds of- pale-green stones used in China for 

 ornaments, called feitsui, has the high specific gravity of zoisite, but 

 it has nearly the composition of oligoclase, if the iron and magnesia 

 be excluded ; analysis by Damour affording Silica 59 17, alumina 

 22*58, iron protoxide 1 56, magnesia 115, lime 2 -68, soda 12 '93 =100 07. 

 It is the material of some of the ornaments in the Swiss lake-dwell- 

 ings. 



Allanite. — A cerium epidote, of a pinchbeck -brown to brownish- 

 black and black color, submetallic to pitch-like and resinous in lustre, 

 crystallizing in the monoclinic system, and with the angles nearly of 

 epidote. H.=5'5-6. G.=3-42. 



B.B. fuses easily and swells up to a dark, blebby magnetic glass. 

 Most varieties gelatinize with hydrochloric acid, but not after igni- 

 tion. Found in Norway, Sweden, Greenland, Scotland ; at Snarum, 

 near Dresden ; in Massachusetts, at the Bolton quarry ; in New York, 

 at Moriah in Essex County, Monroe in Orange County ; in New Jersey, 

 at Franklin ; in Pennsylvania, at East Bradford and Eaton ; in Vir- 

 ginia, Amherst County ; in Canada, at St. Paul's. 



Orthite is a variety in long slender crystals. Muromontite, Bodenite, 

 and Michaelsonite are related minerals. 



Gadolinite. A mineral of a greenish-black color, containing lithium, 

 cerium, and barium, from Sweden, Greenland, and Norway. Crystals 

 monoclinic, with 7 A 7=116°. H. =6 5-7. G. =4-45. 



Mosandrite. Eeddish-brown to dull greenish or yellowish-brown 

 silicate of cerium, lanthanum and didymium, calcium, and titanium. 

 H.=4. G =2-9-303. From Brevig, Norway. 



llvaite ( Yenite). In trimetric striated prisms, of an iron-black to 

 grayish-black color. Ia1=U2° 38'. H.=55-6. G.=3 7-42. In 

 composition a calcium-iron silicate in which part of the iron is in 

 the sesquioxide state. From Elba ; Fossum and Skeen in No; ^ay, 

 etc. Also reported as occurring at Cumberland, B. I., and Milk /»ow 

 quarry, in Somerville, Mass. The name llvaite is derived froir the 

 Latin name of the Island of Elba. 



