Red, orange, yellow, green and blue make up the contrasting colors of a 2.6 x 0.56-inch opal discovered more than a decade ago in Australia.

Its contrasting colors give it the name Virgin Rainbow and snagged for it the title of the most beautiful opal in the world.

In 2003, coal miner John Dunstan stumbled upon this fascinating form of silica in the opal fields of the town of Coober Pedy in northern South Australia.

The Virgin Rainbow will finally be available for public viewing next month, as the centerpiece of an exhibit at the South Australian Museum in Adelaide.

Belemnitida, an extinct cephalopod, existed during the Mesozoic era. At the time, plesiosaurs, or prehistoric aquatic reptiles, filled a vast inland in much of South Australia. When these reptiles died, they sank to the bottom of the sea, and for thousands of years had been further buried deeper by sediment.

Over time, the sea dried up and eventually turned into a desert. Acidity levels then increased on the shallow top layer of the sandstone. Weathering sandstone released silica beneath and into a layer of clay, where pockets and bones were buried and carried down via the groundwater.

Acidity levels were further lowered by weathering, making silica gel harden into opals in the decayed animal material, similar to how cakes are poured into molds.

A result of this process, the Virgin Rainbow, has actually sprung up as an opalized fossil from the extinct belemnitida cephalopod.

"You'll never see another piece like that one, it's special," said Dunstan. He also said that with its sparkling rainbow colors, the opal glows in the dark, with more colors coming out in darker light.

"...when you compare it to the other pieces that claim to be the best ever, this one just killed it," added the coal miner who has cut and polished a lot of opals for 50 years.

According to Brian Oldman, Director at the South Australian Museum, the exhibition is one literally millions of years in the making, emphasizing that the opals were formed during a time when dinosaurs still fared the Earth, in a Central Australia that was mostly an inland sea.

"From jewellery to fossils to specimens embedded and in rock, visitors will be treated to a spectacle of unmatched color and beauty," the Museum Director said.

The Virgin Rainbow, along with the Addyman Plesiosaur, will be displayed with a collection of other dazzling opals. The South Australian Museum announced that it will open the exhibition called Opals on Sept. 25.