This is a unique Mexican lace agate with beautiful intricate banding and lace patterns . It is also known as the laughter stone or happy lace . It is associated Mexican fiestas and dancing . 
Crazy lace agate (also known as Mexican Agate) is a banded chalcedony (microcrystalline quartz) that's infused with iron and aluminum and is often brightly colored and complexly patterned. This produces the creamy browns, blacks, greys and golds (and occasional pinks or reds) swirled together in this stone. 
This agate is found exclusively within the area known as Chihuahua, in Northern Mexico