Agate is a banded chalcedony and variety of the mineral quartz. There are hundreds of different types of agate stone and contrary to popular belief, not all display concentric bands or band-like patterns. Although well known for its exceptional colour, stones often occur in shades of black, white and grey but this material often ends up being dyed which apparently makes it more desirable.
Different varieties of agate that can be found around the world often have their own unique name and the first part often but not always, helps with identification. Names may reveal where the stone was mined, its colour or a specific characteristic. Examples include Botswana agate from Africa, dendritic agate known for its dendritic inclusions, lace agates which exhibit wavy lace-like patterns and polka dot agate known for its reddish brown coloured spots. Hundreds of names are in use to describe an endless variety of agates.
To see more of the detail in this agate stone drop by our page on Flickr where you'll be able to zoom in on the original sized photograph.