Mexican Fire Opal : Transparent to semi-transparent in yellow, red or orange to brown body color, with or without play-of-color. In ancient times in India, the Persian kingdom and the Americas the fire opal was a symbol of the most fervent love. It was believed to have been created in the waters of Paradise, in fact the Mayans and Aztecs called it quetzalitzlipyollitli, the 'stone of the bird of paradise'. It is considered the national stone of Mexico where it is found in its volcanic deposits. The only other large concentration of fire opals has been found recently in Brazil. These are yellow to orange, can be cloudy and have no play-of-color. Can contain water anywhere from 3-10% of it's weight, yet it is a very light stone, 46% lighter than Sapphire. It is the birthstone for October and 14th Wedding Anniversary.