AZGem Gems
November, 2001
The World's Most Useful
Gem & Jewelry Monthly Newsletter

Written by Carolyn Doyle for customers of
The Dorado Company
and other visitors to the website who subscribe.


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Usable Gems... and a little opinion.


Gem Diffusion Enhancement


This is a widely accepted practice in the world of gems. Only a small percentage of the stones mined are beautiful enough to be used as gems.

Many potential gems come from the mine with too much or too little color.

For the gem dealer, treatment that reduces of increases the color saturation in a gem increases the value of the gem, and increases the number of saleable gems.

For the consumer, gem treatment increases the supply of beautiful gems… and that keeps wholesale and retail prices low enough that working folks can afford beautiful gems and jewelry.

The diffusion treatment process truly deserves to be called an enhancement.

As you will recall, color in gem crystals is usually caused by atoms of a stray metallic element being incorporated into the crystal structure of the gem.

The details of diffusion enhancement are kept very secret by the enhancers. Each has spent years and a huge amount of money perfecting their particular processes.

However, we do know the basic principles involved. It's done by heating a faceted gem to just below its melting point in the presence of a color-causing element such as chromium, manganese, or iron.

The resulting color change is permanent.

At high temperature atoms of the color-causing element can be induced to migrate into the outer crystal structure of the gem, thereby enhancing the color of the gem.

In nature all this happens as the crystal is growing, so the color usually goes all the way through the stone.

In diffusion enhancement the color may not penetrate very deep into the stone. This may mean the gem cannot be repaired if it becomes chipped.

About twenty years ago a diffusion process was perfected for enhancing corundum… blue sapphire at first, then pink sapphire and ruby.

About six years ago some people in the industry started looking for an environmentally friendly method for enhancing topaz (to replace radiation treatment).

The answer appears to be diffusion enhancement.

Two years ago blue and green topaz was introduced.

Today the process has improved to the point that more than a half dozen shades of blue and green diffused topaz are available.

Also, just now becoming available are several colors and shades of imperial topaz, ranging from yellow, to orange, to red-orange.

The Dorado Company currently has several hundred carats of topaz being diffusion treated in Asia. When we receive the enhanced material, we will include pictures and an evaluation in this newsletter.

In the mean time, Christmas is upon us!

We are selling a lot of gems (especially spinel, blue topaz, and amethyst). And, we're selling a lot of the 7-mm earring studs.

Please order soon to assure delivery before Christmas.


Big Studs

If you haven't checked out the 7-mm stud earrings featured on our website, now is a good time to take a look.

citrine studs, gem stones, gemstones

The earrings make great gifts, and the low prices make them even more attractive!



Free Shipping

Don't forget, we're offering free shipping on all orders over $99.

Just deduct the shipping charge when you fill out the order form. If you forget, we'll deduct it for you.


Until next month… please, visit me anytime at for a great selection of colored gems at great prices.

Carolyn Doyle

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The Dorado Company
P.O. Box 8232
Scottsdale, AZ 85252-8232