A true museum-quality display specimen. The stunning fossil shell is 7.7 x 2.0 x 1.7 cm. It is 31 grams in mass, and has an intense, saturated color that is simply unearthly. The vivid hue is extremely uncommon in these fossils, as is the depth of gemminess, translucency, and color. Normally, the opalization is a surface effect. It is lightly polished on one side, and left natural and raw on the back. The piece fits into the matrix, and is not glued in. The matrix came from the same horizon as the fossil shell, and has a perfectly carved cutout to emplace the fossil for display purposes if you desire - however, as with nearly all such specimens, the piece was removed from crumbly natural matrix (of soft clay) to clean and polish its surface, and so the current matrix piece is not the original matrix from which it came, and is preserved for presentation purposes. 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. Personally, this is my favorite piece in the lot.