How to Buy a Ruby

A ruby is red corundum made of crystalline aluminum oxide. It is identical in composition to a sapphire except for color; rubies are red corundum, while all other colors of corundum are called sapphires. The birthstone for July, rubies are said to have healing powers and can protect against bad luck. Rubies are second only in hardness to diamonds.

Difficulty: Moderate

Instructions

1. Select a good color. Rubies should be red; not pink, purple, brown or orange. The best quality is a deep red with no purple overtones

2. Pick an affordable size. Larger rubies of fine quality are expensive. Finest quality rubies of 1 to 2 carats may sell for over $6,000 wholesale. Buy the largest ruby you can afford without sacrificing quality.

3. Look for inclusions in the ruby. Inclusions are irregularities that can be seen with the naked eye. They might be a fracture in the ruby or a cavity or an irregular formation pattern. Better rubies are clear to the eye, with few, if any, inclusions.

4. Examine the cut. Most rubies are cut as brilliants, which is a faceted cut. Heavily flawed rubies are polished as "en cabochon," which is not faceted. The exception to this is star rubies, which are always cut cabochon. A ruby in the rough is usually shallow. Deeper cuts, rather than shallow cuts, are more valuable.

5. Find out the country of origin. The best quality rubies come from Mogok Stone Tract in Myanmar, formerly Burma, and are called Mogok rubies. These rubies have become increasingly rarer to find. Rubies have been found in other areas of the globe, including Africa, Asia, Australia and North America. The quality of these rubies varies. Thailand has a large portion of the modern ruby market.

Tips & Warnings

• Ask the jeweler what treatment the ruby has received. Many rubies, especially lower quality rubies, have been treated with heat to improve the color and clarity. While this is an old procedure, it also may weaken the ruby. Rubies that have not been altered are more valuable.
• Looking at a ruby through a jeweler's loop will give a close look at the cut and clarity. With practice, a consumer can find imperfections in the ruby.
• Always deal with a reputable jeweler when buying rubies. The naked eye cannot differentiate between a synthetic ruby and natural ruby; only a gemologist with special equipment can tell the difference.