Opal enchanted the Greek poet Onomakritos so much that he compared it to a child’s face in his poem. It was also intensely admired by the Roman philosopher Gaius Julius Solinus, who attributed extraordinary magical effects to the mysterious stone of sixty colours. In his book Naturalis Historia, one of the earliest encyclopaedias of the Antiquity, the Roman naturalist Plínius wrote: “No other gem is more pleasant in appearance to one’s eyes.” Where did those precious opal stones come from? The descriptions of ancient authors contain references to the intense colour scheme and distinctive opalescence that is typical of the Dubník precious opal. Experts therefore tend to believe that precious opals of the Antiquity originated in the locality Slánske vrchy.