from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A variety of silica that contains microcrystalline quartz.
- n. A siliceous rock of chalcedonic or opaline silica occurring in limestone.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Massive, usually dull-colored and opaque, quartzite, hornstone, impure chalcedony, or other flint-like mineral.
- n. A flint-like tool made from chert.
from the GNU version of the Collaborative International Dictionary of English
- n. An impure, massive, flintlike quartz or hornstone, of a dull color.
from The Century Dictionary and Cyclopedia
- n. A cryptocrystalline variety of quartz, also called hornstone, petrosilex, or rock-flint.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. variety of silica containing microcrystalline quartz
The Lake Superior iron formations now consist near the surface mainly of interbanded quartz (or chert) and hematite, called _jasper_ or _ferruginous chert_ or _taconite_.
Chert is sometimes called hornstone; also the term chert is often applied to any impure flinty rock, including jaspers.
And why I have begun this column with what seems like a chain of free association is something that will probably become only marginally clear to you when I tell you that it was triggered by the news, last year, of the discovery at the Natural History Museum in London of the oldest known insect fossil, embedded in a chunk of a crystalline rock from Rhynie, S.otland known as chert -- a fossil that dates from the very same S.lurian period, four hundred million years back, that saw the flourishing of the eurypterids that T.S. Eliot's "ragged claws" line unaccountably calls to my mind.
When all you have is a knife (only carbon blades work; stainless is too hard), you may be able to get a spark by striking its back with a sharp stone chip, such as chert or flint.
We don't use the kind of chert that we used to because we don't have the type of chert roads, but this will work out better because it will cut our costs down. "
After an hour or so of exclaiming over the thousands of flakes of chert that littered the ground, we discovered a shoulder-height vein of glistening dark chert and followed it along for a quarter of a mile until the ledge we were walking on pinched out.
As we scraped and dug around the house area, fire pits emerged from under the tough grass, yielding chert flakes, an occasional hammerstone or a scraper, and one melted green glass bead no larger than a pinhead.
The lithic debris was primarily moss agate, a cream-colored chert and the root-beer-colored chert from the four quarries on the property.
Dudley remarked later in a report that the chert materials “represent the entire lithic reduction sequence core, primary, secondary, tertiary, and micro flakes.”
In addition to the flakes we uncovered two dozen fire-scorched rocks, a biface knife, a broken piece of fossiliferous chert that had been heated.