from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. hornfels
from the GNU version of the Collaborative International Dictionary of English
- n. A siliceous stone, a variety of quartz, closely resembling flint, but more brittle; -- called also chert.
from The Century Dictionary and Cyclopedia
- n. A very compact silicious rock, differing but little from flint.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a fine-grained metamorphic rock formed by the action of heat on clay rocks
Chert is sometimes called hornstone; also the term chert is often applied to any impure flinty rock, including jaspers.
"hornstone" type, with porphyritic developments of silicate minerals.
During a ride to a natural tank amongst these rocky elevations, I passed from the alluvium to the sandstone, and at once met with all the prevailing plants of the granite, gneiss, limestone and hornstone rocks previously examined, and which I have enumerated too often to require recapitulation; a convincing proof that the mechanical properties and not the chemical constitution of the rocks regulate the distribution of these plants.
The hills are hornstone and quartz, stratified and dipping southerly with a very high angle; they are very barren, and evidently identical with those on the south bank of the Soane; skirting, in both cases, the granite and gneiss range of Paras-nath.
The flat slabs were generally of slate or hornstone; but many of them, and all the larger ones, were of syenitic granite, split by heat and cold water with great art.
In the bed of the river, whose waters are beautifully clear, are hornstone rocks, dipping north-east, and striking north-west.
On the banks I observed much granite, with large mica crystals, hornstone, tourmaline, and stratified quartz, with granite veins parallel to the foliation or lamination.
Following up the stream I came to some rapids, where the stream is crossed by large beds of hornstone and porphyry rocks, excessively hard, and pitched up at right angles, or with a bold dip to the north.
These hills are of limestone, and rounded, resting upon others of hornstone and jasper.
By the banks of a deep gully here the rocks are well exposed: they consist of soft clay shales resting on the limestone, which is nearly horizontal; and this again, unconformably on the quartz and hornstone rocks, which are confused, and tilted up at all angles.