Gemstone Treatments

by Judy Ellis

These gems are HOT!
I'm learning so much as I get to know our line of gemstone beads - studying up on such semi-precious gemstones as seraphinite and bronzite, and trying to figure out how the Dog Teeth Amethyst earned its name.

(It has nothing to do with canine incisors, I discovered, but everything to do with the Dog Tooth Violet, a wildflower in the eastern U.S. It's evidently not actually a violet; it's more like a tulip, and it gets its name from its "dog tooth" shaped bulbs. Now, that's more than you ever wanted to know, isn't it?)

Heating Stones is just Part of the Gem Business

Nearly all the gemstone beads in WireJewelry's collection are natural stones in their original state.

However, a few such as onyx and sardonyx are labeled as "heated" natural stones.

That made me wonder: could I wear my onyx earrings to the beach?

And what if I accidentally left my new bead bracelet in the oven?

Judy Ellis's Gemstone Treatments - , General Education, , Sardonyx Rectangle Beads

We've often been asked if it's safe to add beads to kiln-fired metal clay pieces.

This led to a discovery tour of heated stones.

The ancient practice enhances stone color, making it richer, darker, or clearer.

Most sapphires are heated.

Without it, they appear murky blue instead of vibrant..

Onyx, too, is a gemstone that you rarely see, well, I'll call it cold. The onyx in three of our beads - onyx, matte onyx and sardonyx - is like most onyx, in that it originated as plain agate.

Judy Ellis's Gemstone Treatments - , General Education, , Matte Onyx beads

These Beads are Cooked - Permanently

Don't worry. Your bracelet won't ruin near the oven.

Gem producers mean intense scorching when saying a stone is "heated."

Stones face extreme temperatures from 500°C to 1,600°C in computer-controlled furnaces.

Heat rearranges atomic structure. It dissolves bubbles or inclusions for clearer, more vibrant gems.

With rubies, intense heat nearly melts the stone. It transforms aluminum oxide into a new crystal structure for brilliant red glow.

Rocks aren't Strangers to Heat

This heat process is nothing the stone hasn't experienced before.

Heating enhances color, continuing the process that began in lava flows.

Left in the earth, it would continue naturally.

Compressing millions of years into a football game's length feels a bit hammy.

Heating is just one of several common treatments

A couple of other stones in our bead selection have been treated.

Our smoky quartz beads have been irradiated to produce their dark-brown color.

This treatment is almost as common as heating the stone.

The flamboyant blue and purple crazy lace agate has been dyed.

The only beads that are not actual gemstones are the cherry quartz & goldstone, which are actually beautified glass

Judy Ellis's Gemstone Treatments - , General Education, , Smoky Quartz beads

Even the early Romans heat-treated stones to transform boring into brilliant, just as our modern gemologists do.

That's because there would be very few colorful - yet affordable - gemstones on the market, as it's very rare for gems to naturally occur in the rainbow hues we love.

Affordable is the key word here. Robert James FGA, GG, gives this example: A rare 3-carat sapphire that comes out of the earth a brilliant blue could cost you upwards of $20,000; compare that with $1,500 for the same-sized sapphire that earned its color through heat treatment.

Some gemstones wouldn't exist without heat treatment.

Citrine is heat-treated amethyst.

Purplish-blue tanzanite starts as dull, reddish brown.

Heated to Last

This process won't affect your jewelry.

Heat treatments create permanent changes. Daily wear won't harm the stones.

Keep onyx and sardonyx away from extreme heat and household chemicals.

Firing stone beads in a kiln is complicated.

Here is a , wonderful chart (36.2KB PDF download) though, that will give you some guidance. Interestingly, it recommends against firing any quartz, from agate to amethyst. Cubic Zirconia stones, however, will stand up to extreme heat - neat!

Know what you're Getting

Buy colored gems from trusted distributors to avoid misinformation.

Reputable dealers know about heat treatments. They must disclose this info, though they may not know full origins for imports.

Most vendors are honest. Still, ask yourself.

WireJewelry partners with reliable U.S. distributors.

You get exactly the bead shown online.

Don't worry. Be happy. Enjoy the vibrant colors!

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