456 RECORD OF SCIENCE FOR 1886. 



iu hexagonal crystals, occasioually of great size (2 inclies across) in 

 Canada, iu Kentiew County, Ontario ; also large dodecaliedral garnets up 

 to nearly 10 pounds iu weight at Salida, Colorado; fine crystallized 

 celestite from Lampasas County, Texas; phenacite from Florissant, 

 Colorado. Some of the cases aie alluded to in the preceding pages. An 

 interesting and novel occurrence is that of garnet and toi)az in litlio- 

 physes iu the rhyolite of I^^athrop, Colorado. The lithophyses are more 

 or less spherical cavities, partially filled by thin curved walls, concentri- 

 cally arranged, and ])roducing rose-like forms. These cavities contain 

 minute crystals of sanidine, garnets of the spessartite variety, and 

 beautiful prismatic crystals of topaz, usually of a pale bluish or wine- 

 yellow color. This occurrence of topaz iu the rhyolite of Kathrop is 

 shown by Cross to be similar to the occurrence of the same mineral at 

 Chalk Mountain, Colorado, and of the Thomas range in Utah. 



The well known locality iu Sharpe's Townshiji, Alexander County, 

 l^Torth Carolina, developed by W. E. Hidden, has recently yielded some 

 remarkable mineral specimens. Among these are some very fine emer- 

 alds, unique iu beauty of color, size, and perfection of form. The largest 

 weighed 9 ounces, and was 3 inches long and If in diameter. The 

 emeralds occurred in a pocket extending 20 feet vertically, 4 feet iu ex- 

 treme length, and a foot across. The associated minerals were green 

 muscovite, rutile, dolomite, monazite, and quartz. Some large crystals 

 of s])odumene (hiddenite) were also found; one of them was 2f inches iu 

 length, and weighed one-half an ounce; its color was in part of the fine 

 emerald color which makes the mineral imzed as a gem. 



NEW MINERALS. 



Argyrodite. — A new ore of silver, exceptionally interesting, as cou- 

 tainiug a new element, Germanium. It was fouud in September, 1885, 

 at the Himmelfiirst mine, near Freiberg, Saxony, and has been named 

 and described by Weisbach, It occurs in small crystals mostly grouped 

 in rounded wart-like or reniform aggregates; also iu masses with a flat 

 conchoidal fracture. They belong to the monoclinic system, showing a 

 prism of 115°, with a clinodome and one prominent hemi-pyramid. The 

 axial ratio is a:h:c (vert.) = 0.G78 : 1 : 0.G14; also /3 =70o. Twins 

 and drillings, sometimes in knee-shaped forms, were observed. The 

 hardness = 2.5; specific gravity = CIO. Luster metallic, color steel- 

 gray, with a tinge of red, but becoming slightly violet with superficial 

 tarnish. The composition has been determined by Winkler, who, after 

 at first finding a loss of 8.} per cent, iu the analysis, succeeded in proving 

 the presence of a new element, to which he gave the name Germanium. 

 The analysis, when completed, gave: 



S Ge Ag Fe Zn 



17.13 G.'J3 74.72 O.GO 0.22 = 99.60 



