This sparkling, iridescent fossil clam shell is 4.2 cm long and is ALL made of opal, translucent and colorful. It is exceptional for these fossil clams, in its translucency when backlit, although it is not of the fire opal iridescence throughout. It is 13 grams in mass. Although lacking in color intensity (although it has good play of color, it is just not intense), it is translucent and does have fantastic 3-dimensional shape and preservation! As typically done, it is lightly polished on both sides to show the surface opalization. These very rare opal-replaced fossil shells were formed 135 million years ago and are unique to Australia. The supply at this famous locality, where the town of Coober Pedy is actually dug into the formation, has been exhausted as mining here is no longer profitable or commercially successful on any scale. These gem-quality specimens hold considerable value simply as opal for carving purposes and represent some of the cream of the crop assembled by a local collector during the 1960s-1980s mostly. Specimens of this quality are simply unavailable on the market. We are honored to present this private collection for the first time.