Page:Popular Science Monthly Volume 28.djvu/848

828 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 County, 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 instructive of the series is a quantity of gem-gravel from Ceylon, containing 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, polished 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 three 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 amethyst 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 centimetres 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 destroyed 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.

We 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 are from South Africa. Superb rutilated quartz (sagenite,flèche 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