Question: I was a bit disappointed with your description of opal wearability as “Poor.” Bit harsh I think. If it’s worn as a ring I could understand the comment, but how about brooches and pendants? Not too much abrasive action on stones in those jewelry pieces. If I were in the market for opals and read your comment, I would be turned off. Maybe add something nice to your comments about these lovely gemstones.
By International Gem Society 2 minute read
black opal jewelry

Jewelry with a black opal stone, 31.8 cts. Photo © Joel E. Arem, PhD, FGA. Used with permission.

Answer: Opals are indeed lovely gems, but they’re also delicate. They require certain precautions for jewelry use.

Why is Opal Wearability Poor?

I have nothing against opal. In fact, I have a genuine fondness for it. My wife has a pendant, brooch, and earrings of Mintabe opals I cut for her. She loves them and wears them with pride.

A gemstone’s wearability grade reflects how easily it can be worn in jewelry. Opals have two significant weaknesses as jewelry stones: a low Mohs hardness and significant water content. This results in a “Poor” grade.

Opals have a relatively low Mohs hardness of 5.5 to 6.5. This means they have a lower hardness than one of the most common hazards jewelry stones face: household dust. With a hardness of 7, household dust can scratch opals.

All opals contain water as a result of how they form underground. Gem-quality opals usually contain from 6% to 10% water. This makes them vulnerable to sudden changes in temperature. Moving from an air-conditioned room to the outdoors on a hot summer day — or from a warm room into a frigid winter night — might cause an opal to shatter. In addition, opals that lose their water content may “craze” (develop cracks) and lose their play of color.

Jewelry Tips for Wearing Opals Safely

I wouldn’t be doing my job well if I didn’t tell novice buyers about opal wearability. However, there are still ways to wear your opal jewelry safely.

Protective settings, especially for ring use, can help ensure you’ll enjoy your opals for many years. For example, bezel settingssolid backings, raised prongs, or cage-type designs can all keep opals safe from blows and scratches. Opal doublets and triplets can also make the stone itself more durable.

Opal ring with bezel setting. Photo © Joel E. Arem, PhD, FGA. Used with permission.

As you note, wearing opals as pendants and brooches will also expose these gems to fewer hazards. Occasional wear is another way to extend the life of your opal jewelry.

Of course, the element of chance also comes into play. (Opals have many symbolic associations with luck, both good and bad). I’ve seen opals in settings that aren’t well-protected that have been worn for decades. Some individual opals gems are pretty durable. Nevertheless, generally speaking, opals are delicate gems. However, if you use protective settings, minimize exposure to risks, and care and store your opals properly, you can still wear jewelry made from these beautiful stones.

Donald Clark, CSM IMG

opal necklace

Opal necklace with raised prong setting. Photo by James Petts. Licensed under CC By-SA 2.0.