United States or Mozambique ? Vote for the TOP Country of the Week !


All night long, stopping only when one or the other fell, they ploughed over basalt and hornblende schist that lacerated their feet, over blanched immensities under the steel moon, across grim, black ridges and through a basin of clay, circled by hills. Strange apparitions mocked and mowed before them, but grimly they gave no heed.

I did not observe in any specimen distinguishable crystals of hornblende or augite; I except the fused grains in the ejected fragments, and in the pinnacle of the little crater, above described.

Many of the latter are magnetite, while the others are hornblende and various ferromagnesian silicates. I did not detect any fragments of volcanic origin. The specimen of argillaceous sandstone is made up of thin layers of fine-grained sand of the same sort as the first, alternating with others containing considerable clay.

I nowhere observed mica in this formation, and rarely hornblende; where the latter mineral did occur, I was generally in doubt whether the mass really belonged to this formation, or was of intrusive origin. Calcareous spar occasionally occurs in small cavities; and nests and layers of epidote are common.

The strata incline towards the chain of the coast, as substances which had not been in fusion might be supposed to do. Can we admit that so many alternating rocks, imbedded one in the other, have a common origin? The nature of the phonolites, which are lithoid lavas with a feldspar basis, and the nature of the green slates intermixed with hornblende, oppose this opinion.

Quartz and feldspar scarcely contain five or six thousandths of oxide of iron and of manganese; but in mica and hornblende these oxides, and particularly that of iron, amount, according to Klaproth and Herrmann, to fifteen or twenty parts in a hundred. The hornblende contains also some carbon, like the Lydian stone and kieselschiefer.

A hundred years had already elapsed since the masons had run up those walls of rusty hornblende rock, and it was even said that the leaden window-sashes, with their diamond-shaped panes of greenish glass, had been brought over from England, in the days of William Penn.

The porphyries containing vitreous feldspar and hornblende, the phonolite, the greenstone, the amygdaloids, and the basalt, have forms almost as invariable as simple crystallized substances.

The hills on the opposite or south side of the valley are composed of compact felspar, with acicular crystals of glassy or common felspar and grains of hornblende, crevices of the stone being coated with films of serpentine or green earth. December 3. The party in proceeding crossed several deep gullies in the neighbourhood of the burning hill; and the road continued to be well marked.

The porphyry, which is of warm brown or chocolate colour, includes many crystals of lighter coloured felspar, and dark crystals of hornblende. The stone would take a very high polish, and for decorative purposes of high class, such as vases, panels and bases for busts and tazzas, etc., it is unequalled in South India, and deserving of all attention.