agate (ăg`ĭt), translucent, cryptocrystalline variety of quartz quartz, one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2.
..... Click the link for more information. and a subvariety of chalcedony chalcedony (kălsĕd`ənē)
..... Click the link for more information. . Agates are identical in chemical structure to jasper, flint, chert, petrified wood, and tiger's-eye, and are often found in association with opal. The colorful, banded rocks are used as a semiprecious gemstone and in the manufacture of grinding equipment. An agate's banding forms as silica from solution is slowly deposited into cavities and veins in older rock. The stones can be artificially stained to produce combinations of color more vivid than those found in the natural state. The cutting and staining of agates has long been centered at Idar-Oberstein, Germany. Important sources of agate are Brazil, Uruguay, and the United States (Oregon, Washington, and around Lake Superior). The moss agate or mocha stone contains visible impurities in the form of dendritic shapes that resemble moss. See onyx onyx (ŏn`ĭks), variety of cryptocrystalline quartz , differing from agate only in that the bands of which it is composed are
..... Click the link for more information. .
Common, semiprecious silica mineral, a variety of chalcedony that occurs in bands of varying colour and transparency. Varieties are characterized by peculiarities in the shape and colour of the bands, which are seen in sections cut at right angles to the layers. Agate is found throughout the world, commonly in cavities in eruptive rocks and in geodes. Brazil and Uruguay are major producers of agates; they are also found in Oregon, Washington, Idaho, Montana, and other western U.S. states. Agate is essentially quartz. Much commercial agate is artificially dyed to make the naturally dull-gray stones more colourful.
agate
..... Click the link for more information. and a subvariety of chalcedony chalcedony (kălsĕd`ənē)
..... Click the link for more information. . Agates are identical in chemical structure to jasper, flint, chert, petrified wood, and tiger's-eye, and are often found in association with opal. The colorful, banded rocks are used as a semiprecious gemstone and in the manufacture of grinding equipment. An agate's banding forms as silica from solution is slowly deposited into cavities and veins in older rock. The stones can be artificially stained to produce combinations of color more vivid than those found in the natural state. The cutting and staining of agates has long been centered at Idar-Oberstein, Germany. Important sources of agate are Brazil, Uruguay, and the United States (Oregon, Washington, and around Lake Superior). The moss agate or mocha stone contains visible impurities in the form of dendritic shapes that resemble moss. See onyx onyx (ŏn`ĭks), variety of cryptocrystalline quartz , differing from agate only in that the bands of which it is composed are
..... Click the link for more information. .
agate
)
Banded agate
(credit: B.M. Shaub)
agate
1. an impure microcrystalline form of quartz consisting of a variegated, usually banded chalcedony, used as a gemstone and in making pestles and mortars, burnishers, and polishers. Formula: SiO2
2. a playing marble of this quartz or resembling it
agate
symbolizes health; supposed to relieve snake and scorpion bites. [Class. and Medieval Legend: Leach, 27]
See : Health
agate
confers this power. [Rom. Folklore: Brewer Dictionary,15]
See : Invisibility
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