| OCR Text |
Show 118 Llteh. Academy of Sciences, resisting chemical ware; also, making of filaments for Arts and Letters in the tantalum has been utilized incandescent electric lights. The amount is very the Grover Pegmatite of this mineral thus far observed in at but few places. The as individual crystals noted limited, being four inches long, one largest of these crystals was approximately is possible, but not It habit. tabular half inch thick, and had a columbite tantalite may commercial "pockets" of that probable, The South Dakota occurrences be found in the Grover Pegmatite. and only occasionally are described, here that to similar are encountered In suf tantalite columbite crystalline aggregates of ore. ficient quantities to be considered .... .... .... .... |
