Gems Notes and Extracts Augusto Castellani, Mrs. John Brogden 1871

22 GEMS.III.AGATE.So called from the Latin name, Achates (A'^ar^s), of theSicilian river now called Drillo, on whose shores thissubstance is found. This term generally indicates agreat variety of semi-transparent quartzes. Agates arefound in almost every part of the earth. Some arefound in the East, some in the West, and the differenceof their constituent parts makes the specific weightvary from 2-5891 to 2-6901.The agate, properly so called, like that of Sicily, isnaturally translucent less ; transparent than crystallinequartz, but yet less opaque than jasper it is too hard:to be scratched even by rock-crystal ; it takes a verygood polish ; it is never found in regular forms, butalways either in nodules, in stalactites, or in irregularmasses. Nevertheless, the agate called chalcedonyfrequently crystallizesin rhomboids. The Sicilianagate is often of a pale or grey colour, veined in avariety of forms ;sometimes it is spreadin reddishvioletspots.The " fasciatella " agate is like a sample of manyin bandsagates united in a single piece, and disposedclose to each other like ribbons or belts. The bandsare sometimes in right lines ;others are curved, andthen of a circular form arranged round a commoncentre.Eye agates consist of those parts of the stone in which