Baskerville and Kanz — Kunzite. 25 



Art. IV. — Kunzite and its Unique Properties / by Charles 

 Baskertille and George F. Kunz. 



In a recent investigation* made by ns on the behavior of a 

 large number of minerals and gems with various forms of 

 radiant energy, including the emanations, as well as on the 

 production of luminescence in some cases by other physical 

 means, the new variety of spodnmene, designated kunzite, was 

 found to be peculiarly sensitive, and to exhibit some remark- 

 able properties. 



In general, as shown by these investigations, the gem-min- 

 erals were little affected by ultra-violet rays : but three species 

 exhibited a high degree of responsiveness to these and to all 

 forms of radio-activity, so far experimented with. These min- 

 erals were diamonds of certain kinds ; willemite (zinc ortho-sili- 

 cate), which in some cases has been used as a gem-stone, and 

 kunzite. The behavior of the last, as noted in various experi- 

 ments, is unique and will be briefly described here by itself. 



A. Attrition and heat. — Kunzite does not become luminous 

 by attrition, or rubbing. Several specimens were held on a 

 revolving buff cloth making 3000 revolutions per minute, so hot 

 as to be almost unbearable to the hand, and still it failed to 

 become luminous. \Yollastonite, willemite and pectolite are, 

 however, very tribo-lumineseent. 



As to luminescence induced by heat alone, it was found that 

 kunzite does possess the property of thermo-luminescence to 

 some extent, with an orange tint and at a low degree of 

 heat. 



2. Electricity. — The mineral assumes a static charge of 

 electricity, like topaz, when rubbed with a woolen cloth. On 

 exposing kunzite crystals of different sizes to the passage of an 

 oscillating current obtained from large Helmholtz machines, 

 the entire crystal glowed an orange-pink, temporarily losing the 

 lilac color. A well-denned, brilliant line of light appeared 

 through the center, apparently in the path of the current. On 

 discontinuing the current, the crystal gave the appearance of a 

 glowing coal. It was not hot, however, and the phospho- 

 rescence lasted for forty-live minutes. 



Three large crystals, weighing 200, 300 and 400 grams each, 

 were attached to copper wires so that the current passed in one 

 instance from below up, and from the other upwards across the 

 crystal — first across the prism, then parallel with the prism. 

 In each instance the crystals became distinctively luminous, a 

 pale orange-pink, and between the two wires a bright almost 



-Science, N. S., xviii, 769, 1903. 



