HISTORY AND LORE OF OPAL

    An opal is most notable associated as a birthstone with the month of October.  As an  anniversary gemstone it applies to the 14th and 18th years of marriage.

     Opal comes from Latin opalus, from Greek opallios, from Sanskrit upala stone, jewel.  It is a mineral that is a hydrated amorphous silica softer and less dense than quartz and typically with definite and often marked iridescent play of colors.  The color various dramatically depending on where the opal is mined.

     Most opal is more than 60 million years old and generally dates back to the Cretaceous period when dinosaurs roamed the earth.  It is found near the earth's surface in areas where ancient geothermal hot springs once flowed. The minerals bubbled up from beneath the surface of the earth and slowly, over the centuries, lined the walls of cracks, vents and underground cavities in the bedrock. Most opal is found where geothermal hot springs dried up during seasonal periods of rainfall and extended dry periods.

     The most striking quality of opal is its ability to refract and reflect specific wavelengths of light. In fact, the term "opalescence" was coined to describe this phenomenon. The size and spacing of the amorphous spheres of silica within the stone refracts specific wavelengths of light; each sphere refracting a single, pure spectral color much like the individual microscopic droplets of water in a rainbow. The interplay of these pure wavelengths of light gives opal its unique visual appeal, and makes it one of the most sought-after gemstones in the world.