October’s birthstone, the Opal: Lightning in a Gemstone

One of the most beautiful and varied gemstones around, the opal—October’s birthstone—has been revered from early days. Bedouins believed they contained lightning and fell from the sky during thunderstorms. Ancient Greeks thought they brought the gift of prophesy and protection. October’s birthstone is a gem like no other.

Interesting facts about opals

• Unlike other gemstones, the opal features “play of color,” meaning the stone’s typical flashes of lights.
• They aren’t very hard (Mohs scale of 5.5-6.5). That’s because they have a high percentage of water (3%-21%). Gem-quality opals usually have about 6%-10% water.
• Healers believe that the opal reflects the mood of the wearer and intensifying emotions and releasing inhibitions. They inspire creativity, inventiveness, and self-expression. 

Types of opals, as per the GIA

• White or light: Translucent to semitranslucent, with play-of-color against a white or light gray background color.
• Black: Translucent to opaque, with play-of-color against a black or dark background.
• Fire: Transparent to translucent, with brown, yellow, orange, or red bodycolor. This material—which often doesn’t show play-of-color—is also known as “Mexican opal.”
• Boulder: Translucent to opaque, with play-of-color against a light to dark background. Fragments of the surrounding rock, called matrix, become part of the finished gem.
• Crystal or water: Transparent to semitransparent, with a clear background. This type shows exceptional play-of-color.

Are opals bad luck?

Opals have been the victims of bad PR throughout the ages—we now know that there’s no truth to those beliefs.

• Ancient Romans loved them, but by medieval times, the stone’s brilliant colors were believed to have magical powers. Sorcerers were said to use black opals to increase their magical powers or focus them like laser beams on people they wanted to harm.
• In the Black Plague, opals were said to lose their brilliance when the wearer died.
• Today, it’s believed that diamond dealers started rumors about opals because they were afraid people would turn to them instead of diamond sparklies.
• Another reason for the myth may be because the stone is so soft that it breaks easily.

Caring for opal jewelry

• You don’t have to soak opals in water or oil to keep them in good shape.
• Never use an ultrasonic cleaner—the vibrations can cause the stone to break.
• Water isn’t a problem for a solid opal, but it can harm a stone that’s been attached to a backing by permeating the glue that holds the layers together.
• Always store opal jewelry by itself so it’s not scratched by other pieces.

How to tell a real opal

According to one Australian source, most genuine opals have irregular surfaces on the sides or back—curved or bumpy—while a man-made stone will be perfectly flat. Be wary if you can’t see its back or side. Also, the body tone should be white or transparent (not dark).

• Sometimes, an opal in less-expensive jewelry is referred to as a “doublet” or “triplet.” A doublet is a thin slice of opal attached to a dark backing; a triplet has a third layer, a clear dome, glued on top of the actual opal.
• If opal jewelry becomes cloudy after a while, it may be a doublet or triplet that’s suffering from “lifting.” This can happen when water has seeped in between the layers and they start to lift.

Protect your opal jewelry (and your heirlooms, silver, watches, and engagement/wedding rings) by starting with an updated professional appraisal. You’ll be glad you did if you need to deal with your insurance company! Contact me at 617-304-0174 or at aimee@ambappraisal.com

Just as the autumn leaves show their beautiful colors in the fall, so does November’s birthstone, the opal. Enjoy the play-of-color in these beautiful stones.

Brilliantly, Aimee