Description
Chalcedony is a cryptocrystalline form of silica, composed of very fine intergrowths of the minerals quartz and moganite. It has a waxy luster and may be semitransparent or translucent. It can assume a wide range of colors, but those most commonly seen are white to gray, grayish-blue or a shade of brown ranging from pale to nearly black.
Madison Blue Chalcedony is rare and highly prized for its rich, velvety blue color and translucency.
Because the original collecting site in Montana was lost to privatization decades ago, most of the available Madison Blue material is “old stock” mined in the 1970s.
