...abundant yellowish to colorless glass base. In all the specimens examined by Mr. Brackett or by us the olivines are more or less completely serpentinized,...rock is dense, hard and tough, and does not crumble markedjy on exposure, as is evidenced by the fact that the highest points in this igneous area are...

...South African occurrences. — ^^ Chemically and mineralogically, however, it much resembles ^^ .^->f the South African rock, although there are certain...tough, and does not crumble markedly on exposure, as is evidenced by the fact that the highest points in this igneous area are exposures of fairly-fresh peridotite....

...polarization due to decomposition. The rock is evidently an igneous intrusive, which probably welled up iu comparative quiet, and solidified not far from the...instance the freshest rock is dense, hard and tough, and docs not crumble markedly on exposure, as is evidenced by the fact that the highest points in this...

...mineralogically, however, it much reseml the South African rock, although there are certain point* difference — notably the absence of inclusions. Peridotites are generally prone to alteration by weather! In this instance the freshest rock is dense, hard and ton and does not crumble markedly on...

...fresh hand specimens, is tough, hard, distinctly porphyritic, and very dark greenish or brownish black. It is therefore in no sense a volcanic breccia, due...tough, and does not crumble markedly on exposure, as is evidenced by the fact that the highest points in this igneous area are exposures of fairly fresh peridotite....

...from the surface. It is therefore in no sense a volcanic breccia, due to explosive eruptions, as are the South African occurrences. Chemically and mineralogically,...difference — notably the absence of inclusions. April 9, 1910. THE MINING WORLD Dust Explosions in Coal Mines.* BY GEORGE S. RICE. The extremely valuable...

...occurrences. Chemically and mineralogically, however, it much resembles the South African rock, though there are certain points of difference — notably the absence of inclusions. Peridotites are usually prone to alteration by weathering. In this instance the freshest rock is dense, hard, and tough,...