AZGem Gems
March, 2002
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.

Gold Mountings

By far, the most popular metal used in fine jewelry is gold. For fine jewelry featuring colored gems this is especially true.

The color and shimmer of yellow gold seems to be the perfect companion to a fine colored gem.

The basic designation for gold purity in the U.S. is karats, commonly abbreviated as "K".

For some obscure reason, presumably dating back to an ancient measuring system, gold purity is expressed in 24ths.

Twenty-four karat (24K) is pure gold... but pure gold is too soft to be used in jewelry. It doesn't wear well and it bends and scratches easily.

So we mix (or alloy) pure gold with other metals to make it harder. The other metals used vary, depending on what other characteristics we want in the metal.

Eighteen karat gold (18K) is 75% gold and 25% other metals.

Fourteen karat gold (14K) is 58% gold, and 42% other metals.

Nothing less than ten karat (10K) gold can be sold as gold jewelry in the U.S. by law. However, 10K is not used in "fine" jewelry.

Gold Weights

Gold weights are commonly expressed in troy ounces, pennyweights, and grams.

There are 12 troy ounces (oz t) in a troy pound. Troy weights don't really relate to much of anything else, except that gold bullion prices around the world are quoted in troy ounces.

A slightly less obscure unit of measure is pennyweight (dwt). There are 20 pennyweight to the troy ounce. Mounting manufacturers sometimes use this unit of measure.

The most common unit of weight used today is grams (g), a metric unit of measure. There are 31.1 grams per troy ounce.

Gold Colors

Gold is a color and a metal. The color of the metal doesn't always have to be gold… isn't this fun!

A little earlier we talked about alloys. Depending on the metals used as alloy, you can change the color of gold!

A near-natural yellow gold color is maintained by alloying with copper and silver.

Alloying with just copper produces rose gold.

To get white gold you alloy with palladium (or maybe platinum), zinc, and copper.

Alloying with silver, copper, and zinc gives you green gold.


The piece of metal jewelry that a gem is mounted in is referred to as a mounting… or a setting, the industry just doesn't seem to be able to decide.

There are a number of mounting manufacturers around. All of the big ones sell exclusively to the trade (people in the jewelry business, such as jewelry shops, findings dealers, and trade shops).

People not in the trade who are looking for a mounting for a loose gem they own, usually buy from a jewelry shop.

Jewelry shop catalog prices for mountings are usually three times cost, so price negotiation may be appropriate.

Other costs include shipping, a head if needed, and stone setting.

Here are links to a couple of mounting manufacturer's websites with pictures of mountings.

Leo Ingwer Inc

Ptak Bros

I have used both of these manufacturers with good results.

Some manufacturers show their mountings without stones set. Others put stones in the pictured mountings to better show how the mounting will look when the jeweler's or customer's stone is set.

But when a mounting is received from the manufacturer there are no stones set… just empty sockets (heads) with prongs sticking up.

(There is an exception to this rule, and we'll talk about it next time.)

Most mountings are cast as a single piece (molten gold forced into a mold) rather than fabricated, and the heads for setting stones are built into the mounting.


Sometimes they leave off the head for the center stone. The jeweler/trade shop then supplies the head. This way the jeweler has choices (within reason) as to the size and shape of center stone to set.

Unattached heads, and any number of other small parts such as clasps and jump rings used in making jewelry are called "findings."

Here is a link to a findings catalog.

I have not used this company.

Most towns have one or more findings dealers.

Trade Shops

A trade shop is where the piece of jewelry gets done. Trade shops are staffed by one or more goldsmiths/bench jewelers.

These people are the ones who actually produce custom jewelry, do stone setting, and make jewelry repairs.

Some work in jewelry stores and some are independent, working in back rooms in your local jewelry district. By the way, I've never seen a decent one working in a quick fix shop in a mall.

My advice is to stay far away from the "quick fix" people. There's enough risk that a stone will break, or a mounting will melt while being worked on by a trained craftsman.


Free Shipping

Don't forget, we offer 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 for a good selection of colored gems at great prices.

Carolyn Doyle

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