This chalcedony and quartzine plate is from Barros Cassal in Rio Grande do Sul, Brazil. These two minerals are silcates and contain the elements Si and O. Other trace elements can be incorporated into the crystal lattice causing a wide range of colors and crystal morphologies. This specimen consists of a plate of wavelike and circular patterns of chalcedony and its quartzine variety. These patterns are created by the minerals growing at different rates.The patterns on the display side are covered with micro quartz crystals.They have a sparkling luster and vary in colors from reds to blues. – quite attractive – It measures 5 1/4 x 4 x 1 1/2 inches or 133 x 102 x 38 mm.