Fire Opal

It is in Mexico that the most significant fire opal deposits in the world lie. Rock strata containing opals run through the Mexican highlands, with their many extinct volcanoes. With a few exceptions, the gemstone, which lies hidden in cavities and crevices, is extracted in open-cast mines, the work giving rise to impressive canyons with walls up to 60 metres high and labyrinthine passages which wind their way through the mining areas. Sometimes, these orange-red gemstones are also found in other countries, in Honduras or Guatemala, in the USA, Canada, Australia, Ethiopia and Turkey, but these are mostly sites of little or no economic significance. With Brazil it is a different matter. Several years ago, in an agate mine near Campos Borges in the South Brazilian State of Rio Grande do Sul, fire opals coloured yellow to orange were discovered. They distinguish themselves by their beautiful colour, often with slight clouding, but without play of colour. Their warm, expressive orange comes in all varieties from yellow to light red, sometimes with a brownish undertone. What is particularly remarkable is the sheer size of the raw stones. Some of them are as big as a man's fist, which opens up completely new possibilities in the way they can be worked. Today, these Brazilian fire opals are setting new trends in the fascinating world of gemstones.