Description

Among the best-known varieties of banded chalcedony is the stone often known as Mexican Crazy Lace Agate. The hardness of the material makes it a joy to cut, while the intricate patterns have made it a favorite since the 1950s. This unique agate forms into many different patterns in many colors, but the stones generally have a common “theme.”
Mexican Crazy Lace Agate, henceforth referred to as Mexican Agate, is a banded chalcedony variety. Like many agates, it’s found primarily in limestone. The nodules vary widely in color, but they generally have a few common patterns.

Agates mostly occur as nodules in volcanic rocks or waters containing Silica in solution which is possibly derived from the decomposition of Silicates in the lava.  The Siliceous matter is deposited in regular layers resulting in the banded or striped formation.  It is very unlikely that you would ever find an exact duplicate of any type of Agate, Brazilian or other.