KUNZITE, koon'tsIt, the name of a precious stone found in southern California; so called in honor of Dr. George F. Kunz, the special agent in charge of precious stones, United States Geological Survey, since 1882. It is a brilliant gem and is between the topaz and pink sapphire in color. A rose-lilac is the tint which marks this stone, a color new among gems; and its radiance is peculiar and beautiful.
Kunzite was brought to light in 1902 near Pala, in San Diego County, Cal., and was sent for classification to Dr. Kunz, the eminent mM eralogist of New York. Much attention was attracted by the beautiful lilac-colored crystals, for nowhere in the country, not even in the American Museum of Natural History at New York, which has the finest collection of spodu mene, under which the new gem was classed, had there been seen such remarkable and per fect specimens as these. Dr. Kunz identified the gem and described it; but Dr. Charles Basker ville, professor of chemistry in the University of North Carolina, finally subjected it to ultra violet light, then to the rays of high penetra tive power, and lastly to the bombardment of the corpuscles shooting out from radium, which resulted in some wonderful effects new to the scientific world. Of these effects Dr. Charles Baskerville, who took the liberty of naming the gem for his friend, gives the fol lowing account : •0n examining this gem we directed our at tention to discovering the effect of radium on precious stones. It was shown early in the ex periments of the French mineralogist, Curie, that many diamonds phosphoresce, that is, glow in the dark, after being exposed to the emana tions of radium. All diamonds phosphoresce
with radium, as we learned by applying the test to about two thousandgems collected from Th some fifteen thousand. The gem in which we were particularly interested belongs to the class of spodumene. Mineral spodumene is usually obtained in large opaque whitish crystals, but from time to time small specimens, often richly colored and transparent, are found. The three characteristic varieties of the latter are a clear yellow gem spodumene of Brazil, the green hid denite, or lithia emerald of North Carolina, and the lilac sometimes found in Connecticut. These are without doubt remnants of large specimens, which must have been elegant. Spodumene is very subject to alteration and has usually lost all its transparency and beauty of tint') The California spodumene crystals are of a rose-lilac tint, varying with the spodumene di chroism, from a tinge when observed transversely to the prism, to a rich amethystine hue longitudinally. No such crystals of spodu mene have ever been seen before, and the dis covery is of great mineralogical interest. The crystals have been etched by weathering and have a twinning like the hiddenite variety. When cut and mounted parallel , tp the base, they yield gems of great beauty. Baskerville, Kunz and Crookes have found this almost as luminously responsive to the action of radium as the diamond.