It’s the month so fun, you can’t have just one…birthstone, that is! October is a month with two recognized birthstones…opal and tourmaline. Both are beautiful in totally different ways and both have interesting characteristics and history. We will be talking about tourmaline next time around, so this week let’s look at 10 cool facts about opal…
1. There are opals on Mars! NASA revealed in 2008 that opal deposits had been discovered on Mars. What makes this particularly fascinating is that it is an indicator that there may have once been life on Mars, as opal is composed by water evaporating and leaving behind deposits of silica that become precious opal.
2. Opallios is the Greek word for Opals meaning “to see a change of color,” while the Roman word for Opal is Opalus, which means “precious stone.”
3. Opal has long been considered a Lucky gemstone…and this goes back thousands of years! Opals were worn by rulers and royalty with the belief that it would ensure their safety, protect their power and even ward off evil. This belief was taken to the extreme when some would actually grind up opals and eat them to keep evil spirits away and prevent nightmares.
4. About 95% of the earth’s opals come from Australia and the native aborigines have long believed that the dynamic colors in precious opal are from the base of a rainbow where our creator’s foot touched the earth to bring us harmony. Incidentally, the incredible color display in precious opal is because of literally millions of tiny spheres of silica which refract light and cause spectral colors. Amazingly, these spheres have to be of a uniform nature and just the right size to create enough color for our eyes to process.
5. Queen Victoria loved her gemstones. Diamonds, sapphires, rubies…she loved them all, but her favorite? You guessed it. Opal.
6. There are basically only two main types of opal. Common opal is white, with minimal (if any) color display at all. Precious opal has a vibrant color display or, in the case of fire opal, a deep reddish orange color. Fire opal can occasionally be a bright pink and the highly prized black opal variety is more rare than diamonds!
7. Opals should not be worn if you will be anywhere there is a major or sudden temperature change, such as going out on a hot summer evening and then going inside to a restaurant or movie theatre where it is cold. Opals are fragile and these sudden changes in temperature can cause them to fracture or “explode.”
8. Opals take a very long time to form…like millions of years. 1cm of opal takes around 5 million years to form and solidify. The historic theory is that 20 million years ago or more, parts of Australia were flooded with silica-rich water. As the water evaporated, silica deposits formed in crevices and boulders eventually turning into opal.
9. Speaking of fragile, when caring for your opals be very careful. Opals are not hard gems like a ruby, diamond or even October’s other birthstone, tourmaline, so don’t wear your opals when you’re doing any physical activity or even cleaning around the house because it won’t take much of a bump to cause it to crack. You should also never clean your opals in an ultrasonic cleaner.
10. If you’re not wearing your opals, it’s a good idea to store them wet (unless your opal is a doublet or a triplet). Wrapping them in a wet napkin inside a ziploc bag is a good way to store them. Gem collectors often store their raw opal specimens in vials or jars of water, as it keeps them from drying out too much and ultimately cracking.