Base-Cut Brazilian Agate GeodeBrazilian Agates are found in the southern states in basalt formations from 4 to 40 feet deep and at elevations of about 2500 to 3500 feet above sea level. Agate is a variety of silica composed of alternating layers of various colored chert or quartz. Agates were named after the Acate River in Sicily where the stones were originally found. The most accepted theory as to how these Agates formed is that as lava cooled, gas and steam accumulated to form