Noun
A cryptocrystalline, translucent variety of quartz, having usually a whitish color, and a luster nearly like wax.
Source: Webster's dictionaryLandscape agate is chalcedony with a number of different mineral impurities making the stone resemble landscapes. Source: Internet
Many semi-precious gemstones are in fact forms of chalcedony. Source: Internet
The more notable varieties of chalcedony are as follows: Agate Agate Agate is a variety of chalcedony characterized by either transparency or color patterns, such as multi-colored curved or angular banding. Source: Internet
The color of chalcedony sold commercially is often enhanced by dyeing or heating. Source: Internet
This is thought to be because chalcedony is extremely finely grained (cryptocrystalline), and so has a very high surface area to volume ratio. Source: Internet