|Mineral||variety of mineral Agate|
|Formula SiO2] AGATE|
|O||Oxygen||Other no metal||53.25%|
Agate is a variety of chalcedony, a rock consisting mainly of silica, alternating with microgranular quartz. The agate is characterized by its fineness of grain and the wide variety of colors and tones in which it can appear. Agates can be found in various types of rocks, but are generally associated with volcanic rocks and can be common in certain metamorphic rocks. Agate is considered to be a fine stone. The name agate refers to a Sicilian river in which it is found in quantity: the Purchases.