Brazilian Agate like any other agate is a microcrystalline quartz, also known as Chalcedony. A true agate is said to have banding. Banding distinguishes agate from other forms of Chalcedony. However agates such as moss agate, plume agate, dendritic and others with more than one color have traditionally been called Agate, even though they lack banding. Brazilian agate is a true banded agate. Brazilian Agate has many colors, such as orange,blue gray,gray,yellow,white,tans and browns. The colors of iron oxides. Heat treating can richen these colors.