Opals can be set in silver or similar white metal alloys, such as white gold or platinum. There is a myth that believes that wearing an opal ring on the index finger on Friday helps you get its benefits.
Mexican Opal was formed in the fiery and lengthy Mexican volcanoes. The water seeps into silica-rich lava and helps fill cracks and hollows to create fire opal. The remaining water is retained within the silica's structure as it hardens into a gel under heat and pressure. As a result, lava flows contain small fire opal pebbles embedded in them.