The mining of opals dates all the way back to the ancient Romans, when the gemstones were extracted from areas that are now part of the Czech Republic. Perhaps the oldest known opals, however, are 6,000-year-old ornaments that were discovered by archaeologists in African caves. Rarer than rubies and emeralds, gem-quality opal represents only a very small percentage of all the opal that is mined in the world.
A commonly used component in jewelry, the gold used in the metallic combination must be at least 10k to be considered vermeil. Today, vermeil is produced through an electrolysis process.
Keep your opal jewelry away from direct sunlight and avoid impacts to it as well as exposure to chemicals. To clean it, use water mixed with a little bit of vinegar, brushing it softly with a gentle toothbrush. When done, rinse with clean water. Avoid vigorous polishing of your vermeil jewelry so as not to destroy the gold coating, and never expose it to moisture. Keeping it in a zip-lock bag will prevent moisture and humidity from attacking it.