agate
/ˈaɡət
/noun [mass noun]
1An ornamental stone consisting of a hard variety of chalcedony (quartz), typically banded in appearance.Silica precipitated from aqueous solution at low temperatures gives cryptocrystalline varieties such as opal, jasper, chalcedony, agate, carnelian, onyx, flint, and chert....
- Slowest-forming and most beautiful of all, huge crystals of amethyst, agate, chalcedony and rock crystal grow where condensed water has managed to seep into naturally insulated rock crevices.
- My necklaces are made mainly of semiprecious stones, such as agate, quartz, amber, rock crystal and jade.
1.1 [count noun] A coloured toy marble resembling a banded gemstone.You have to be on your mettle to snag them agates (especially with some monster thug trying to put a lump on the back of your noggin)....
- Agates, the gold standard of marbles (called aggies), came in a rainbow of subtle colors with overlaying colored patterns that made them look like beautiful, semi-precious stones.
- I do remember we played for keepsies and I won a nice collection of clearies, cat-eyes (the purple/green combos were my favorites), a few highly prized speckled eggs, aggies (agates), alleys (alabaster/marble), steelies, and even a few boulders.
Origin
Late 15th century: from French, via Latin from Greek akhatēs.