Gems : Chalcedony

Chalcedony is another name for agate, although ‘agate’ is usually used to describe the banded varieties of chalcedony. Many agates are naturally coloured, while others are stained for decorative effect. Varieties include chrysoprase, cornelian, carnelian, sard, sardonyx, onyx, plasma, bloodstone, and myrickite. There are many varieties of agate with different names depending on their appearance, such as moss agate. Jasper, whose impurities cause heavy pigmentation, also belongs to this group.