828 THE POPULAR SCIENCE MONTHLY. 



trast of the bluish-green stone on the background of the chocolate- 

 colored matrix. 



Hematite is exhibited, cut in the form of balls and in a cut intaglio, 

 and a cut, one-carat rutile, from Alexander Countj^ North Carolina ; 

 these so closely resemble the black diamond in color and luster as to 

 have been mistaken for it when first found. 



A dark, almost black hypersthene, from Norway, shows a pleasing 

 bronze-like reflection on the dome of the cabochon. One of the most 

 instructiA'e of the series is a quantity of gem-gravel from Ceylon, con- 

 taining sapphires of various colors, chrysoberyl, zircon, quartz, and 

 other stones, 



A series of the American stone, Thompsonite, found as pebbles in 

 the Lake Superior region, presents some fine cut stones, with the circles 

 from one fourth to three fourths of an inch across. A few large, pol- 

 ished pieces measure over one inch across. Some small pebbles of 

 Lintonite found with the Thompsonite are also polished. 



The quartz array is very instructive : it begins with a two-and-a 

 half -inch Japanese crystal ball, and an eagle seal throe inches high, 

 of Russian cutting ; cut citrines, cairngorm, and the so-called smoky, 

 Saxon, or Spanish topaz, eleven of the dark -purple amethysts from 

 Siberia, often wrongly called Oriental amethysts, and a set of seven 

 from Brazil, show all the changes from light pink to dark purple. 



Perhaps the most unique gem of the collection is a piece of ame- 

 thyst that was found at Webster, North Carolina, and deposited here 

 by Dr. II. S. Lucas. The present form is just such as would be made 

 by a lapidary in roughly shaping a stone, preliminary to cutting and 

 polishing it. It now measures seven centimetres in length, six cen- 

 timetres in width, four centimetres in thickness, and weighs 136*5 

 grammes. It was turtle-shaped when found, and this was said to have 

 been the work of prehistoric man. This shape was unfortunately de- 

 stroyed by chipping it to its present form. It is perfectly transparent, 

 being slightly smoky and pale at one end, and it also has a smoky streak 

 in the center. This coloring is peculiar to the amethyst, however. 

 There are also a three-quarter-inch yellowish quartz cat's-eye from 

 Ceylon, and a three-carat green one from Hoff, Bavaria, and a native 

 Indian necklace from Ceylon, composed of numerous yellowish quartz 

 cat's-eye beads of about three carats each. 



"NVe have, then, a beautiful series of the brown-quartz cat's-eyes, 

 so-called crocidolite cat's-eyes (also called tiger-eyes), in fine slabs, 

 balls, buttons, etc., which is really a combination of crocidolite fibers 

 coated with quartz. This incasing renders it harder than unaltered 

 crocidolite, which is to be seen here together with it. All these arc 

 from South Africa. Superb rutilated quartz (sagenite, ^^cAe d^amour, 

 Venus-hair stone, or Love's arrows), in the rough and in cut form, 

 are from North Carolina. Rhode Island contributes black hornblende 

 blades in quartz, and green actinolite in the same (the Thetis-hair 



