Love these beads with their pieces (pezatto in italian) of 24kt goldfoil and .925 sterling silver foil under transparent colors of Moretti glass. The base is black underneath the gold and silver foils. Size is approximately 38mm in length and about 30 across and slightly puffy in the middle (about 12-13mm thick with about a 1mm diameter hole which runs through the center of this authentic Murano Glass Bead. They are perfect for a pendant bead as a focal for your Venetian Jewelry. They appear as bicolor due to the use of gold and silver pieces. The use of gold or silver changes the color as gold produces a warmer darker effect while the silver produces a shiny effect and lighting of the color. The colors on this one are Amethyst (purple) Murano Glass over the gold and silver foils giving the two-toned effect.