378 Revieivs — Butlers Handbook of Minerals. 



deposit. In fact, they appear to form a connecting link between the 

 two types. This theory is borne out by the character of the 

 mineralization of the country rock alongside tbe greisen streaks in 

 the stock work deposit. The rock is pyritized (pyrite andpyrrhotite), 

 and the felspars altered to sericitic aggregates. 



The Hubble. — The richer patches of rubble lie within 100 yards of 

 the greisens on the steeper ground and within about 25 yards on the 

 fiat ground. 



Tests of this rubble indicate that the yield of wolframite (the 

 scheelite as noted above being rejected) varies from 2 to 8 lb. per ton. 

 In this estimate the occasional lumps of coarse wolframite are not 

 included, and fine wolframite and scheelite in lumps of rock and free 

 are also not included, since they are rejected. 



In the instance of the western end of the Lunar Block reef it was 

 stated that early in 1916, 1,600 lb. of wolframite was picked up from 

 the surface by hand without any appliances, without even a prospecting 

 pan, notwithstanding that the ground had been broken, turned over, 

 and picked on at least one previous occasion. 



Where the rubble is being more thoroughly tested, the ground, 

 made up of angular quartz fragments, brown-weathered greisen, and 

 sandstone-like aplite in a matrix of red loam, is hand-jigged on 

 rocking-screens, the coarse wolframite being hand-picked from the 

 screens. The fines are concentrated in a 5 ft. rotary diamond 

 washer, which recovers the tungsten minerals and even the fine heavy 

 minerals. The concentrate is then panned by hand. The coarse 

 wolframite (pieces over half an inch) are picked by hand and the fines 

 re-panned. Any coarse wolframite with adhering quartz is pestled 

 and panned. The coarse and medium concentrate so obtained is 

 remarkably clean wolframite. The finest concentrate consists of 

 wolframite and scheelite, with a certain amount of quartz, felspar, 

 epidote, hornblende, mica, zircon, and tourmaline, together with 

 a trace of gold, and a fairly large quantity of ilmenite, limonite 

 cubes, and magnetite. The finest concentrate is rejected under 

 existing circumstances, but on a larger scale of operations concen- 

 trating tables and magnetite separators may be expected to give 

 profitable results. 



EBVIEWS. 



I. — A Pocket Handbook of Minerals. By G. Montague Butler. 

 Second Edition, pp. x + 311, with 89 figures in the text. New 

 York, John Wiley & Sons ; London, Chapman & Hall, Ltd. 

 No date. Price lis. 6d. net. 



THIS handy little treatise by the Professor of Mineralogy and 

 Petrology in the University of Arizona has met with such 

 a large demand that a second edition has been called for. The 

 original scope and plan proved so satisfactory that no change as 

 regards them was made, and the only difference in this edition is 

 that additions have been made here and there to the original text 

 where experience has suggested the need, and, of course, all 

 typographical errors that have come to light have been corrected. 



