Stone of Venus
Chrysoprase oval cabochon with bead wire accent and sterling silver feather component and milgrain edge band cuff bracelet, wears somewhat loosely at the wrist 
Called the stone of Venus, is the rarest and most valuable rich apple-green gemstone in the chalcedony family and was often mistaken for emeralds by ancient jewelers.
Chrysoprase is a gemstone variety of chalcedony (a cryptocrystalline form of silica) that contains small quantities of nickel. Its color is normally apple-green, but varies to deep green. The darker varieties of chrysoprase are also referred to as prase.