3.8" Polished Laguna Agate Slice - Mexico

Laguna agate is a highly sought after variety of banded chalcedony. It often forms in bands of red, pink, white and/or scarlet hues, with some specimens containing bands of brown and golden yellow chalcedony. The first documented finds of this agate occurred in the late 1940's and since then have been extracted from several sites near Ojo Laguna, Chihuahua, Mexico. These agates are believed to be roughly 38 million years old.

Like many other agates, Laguna agates form by deposition of microscopic silica crystals in concentric layers within cavities of rocks. The colors of the agate are dependent on impurities within the silica-rich solutions, of which are often supplied by the surrounding rock.