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Updated: May 20, 2025
In the case of quartzite mountains, the conical form is due to atmospheric influences acting on a rock of uniform composition, traversed by numerous joints and fissures crossing each other at obtuse angles, along which the rock breaks up and falls away, so that the sides are always covered by angular shingle forming slopes corresponding to the angle of friction of the rock in question.
In the middle of the Ryans' neighbouring field there is a block of quartzite, as big as a small turf-stack, which gleamed exceedingly white from amongst the deep muffling greenery of the potato-plants. Mrs. Joyce had been praising their thriving aspect to old Paddy, who, however, was disposed to express a gloomy view of them.
Hard and fine-grained rocks, such as granite and quartzite, are often not only ground down to a smooth surface but are also highly polished by means of fine rock flour worn from the glacier bed. In other places the bed of the glacier is rough and torn.
QUARTZ SCHIST is produced from quartzite by the development of fine folia of mica along planes of shear. All gradations may be found between it and unfoliated quartzite on the one hand and mica schist on the other.
By the side of a water-hole that is sheltered by a tall gum-tree rises a curiously gnarled and weather-beaten face of quartzite rock. About twenty feet from the base a ledge juts out. When the totemites hold their ceremony, they repair to this ledge.
They might be looking for Bart Steele by now, but they weren't looking for David Briscoe of Aldebaran. He might just as well relax and enjoy the trip. He went down to the Observation Lounge. It had been darkened, and one whole wall of the room was made of clear quartzite. Bart drew a deep breath as the vast panorama of space opened out before him.
Now recapitulate: The black gneiss below, 800 feet in thickness; the variegated quartzite, 800 feet in thickness; the cliff sandstone, 500 feet in thickness; the alcove sandstone, 700 feet in thickness; the red wall limestone, 1,600 feet in thickness; the banded sandstone, 800 feet in thickness; the tower limestone, 1,000 feet in thickness.
QUARTZITE, or QUARTZ ROCK, is an aggregate of grains of quartz which are either in minute crystals, or in many cases slightly rounded, occurring in regular strata, associated with gneiss or other metamorphic rocks. Compact quartz, like that so frequently found in veins, is also found together with granular quartzite.
In winter some of the characteristics of the Grand Canyon are emphasized. The black gneiss below, the variegated quartzite, and the green or alcove sandstone form the foundation for the mighty red wall. The banded sandstone entablature is crowned by the tower limestone. In winter this is covered with snow.
Numbers of these articles are now being cut and sold to tourists along the line of the Atchison, Topeka, and Santa Fe Railroad. The compact quartzite of Sioux Falls, Dakota, is being quarried and polished for ornamental purposes. It is known and sold as "Sioux Falls jasper," and is really the stone referred to by Longfellow in his Hiawatha as being used for arrow heads.
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