agate(redirected from Dendritic agates)
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1. A fine-grained, fibrous variety of chalcedony with colored bands or irregular clouding.
2. A playing marble made of agate or a glass imitation of it; an aggie.
3. A tool with agate parts, such as a burnisher tipped with agate.
4. Printing A type size, about 5 1/2 points.
[Middle English achate, agaten, from Old French acate, agate, alteration (influenced by Greek agathē, good) of Latin achātēs, from Greek akhātēs.]
1. (Minerals) 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. (Individual Sports, other than specified) a playing marble of this quartz or resembling it
3. (Printing, Lithography & Bookbinding) printing Also called: ruby US and Canadian (formerly) a size of printer's type approximately equal to 5 point
[C16: via French from Latin achātēs, from Greek akhatēs]
dialect Northern English on the way
[C16: a-2 + gate3]
(Biography) James (Evershed). 1877–1947, British theatre critic; drama critic for The Sunday Times (1923–47) and author of a nine-volume diary Ego (1935–49)
1. a variegated chalcedony showing curved, colored bands or other markings.
2. a playing marble made of this substance, or of glass in imitation of it.
a. a 5½-point type.
b. a type size smaller than that used for news text, esp. in classified advertisements.
[1150–1200; « Medieval Latin achātēs < Greek achatēs]
A type of very fine-grained quartz found in various colors that are arranged in bands or in cloudy patterns. The bands form when water rich with silica enters empty spaces in rock, after which the silica comes out of solution and forms crystals, gradually filling the spaces from the outside inward. The different colors are the result of various impurities in the water.