Zimagal Monthly Magazine - Volume One, Issue Ten

Introduction
Much has been written on this subject over the years. Gems have long fascinated mankind, and from very early times they have been used to adorn man and woman alike. The ancient peoples of Central and South America did very elaborate gold work and created jewelry that exists to this day. Likewise the people of Egypt. Often such finely wrought items were embellished with gems and minerals of the region.

Today, the tradition of fine jewelry making and stone cutting goes on. I will merely be skimming the surface of this vast and fascinating subject in this article, touching briefly on some of the most valuable and popular gems today, with a special focus on opal, the October birthstone.

Diamond
Diamond is pure carbon. Its name comes from the Greek adamas, meaning "invincible," in recognition of its exceptional hardness, which makes it resist any form of abrasion by other minerals.

Gem quality diamonds are found in about 20 places in the world, but the largest producer is South Africa. In 1990, a 3.03 carat diamond crystal was found in Crater of Diamonds State Park in Arkansas. Earlier this year, it was cut into a perfectly cut D-flawless 1.09 carat stone.

Question: What are the four Cs of diamond grading?

The market value of diamond is determined by complex grading systems that divide them into a wide range of different categories.

Answer: Color, Cut, Clarity, and Carat weight

The most typical cut for a diamond is the round brilliant, which best displays the gem's unique characteristics. Diamonds are also cut into oval, marquise, pear, rectangular, square, and heart shapes. Some fancy diamond shape cutters get really fancy and cut stars, kite shapes, and even Christmas trees!

Old cuts that are still available on the market include the Old Mine and Old European cut, which are variations on the brilliant cut, and rose cuts, which have flat bases and triangular cuts on the top.

Simulants and Synthetics
Diamonds have many imitators, but none can match the beauty of the real thing. For many years, Cubic Zirconia, a synthetic colorless diamond impostor came the closest. Now there is a new simulant, synthetic Moissonite, on the market. It joins a crowd of others, including strontium titanate, mirror-backed glass, synthetic rutile, YAG, GGG, and synthetic colorless corundum and spinel. A reputable jeweler can tell the difference, many by the naked eye. After several years in the jewelry business, I can even spot a CZ from 100 paces.

A synthetic diamond is a diamond which is man-made, not found in the ground. The first synthetic diamonds were produced by GE in 1955, but all were industrial grade. Today, the majority of synthetic diamonds are produced for use as industrial-grade abrasives. Gem-quality synthetic diamonds have also been produced, and someday may become important to the jewelry industry.

Diamond Color
The vast majority of diamonds are colorless or yellowish. However, diamonds can be found in varying shades of brown, blue, pink, red and even purple. Some natural fancy colored diamonds command a much higher price than colorless diamonds. More affordable are colored diamonds by which the color is created by irradiating the stone.

Left: The Hope Diamond, a famous, deep-blue diamond of 44.5 carats is in the gem collection of the Smithsonian's National Museum of Natural History.