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Ruby is the most valuable variety of the corundum mineral species, which also includes sapphire.

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Fine Mogok Ruby

This fine 2.58-ct. ruby is from Myanmar’s classic Mogok deposit.

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Ruby’s extraordinary red color is caused by traces of chromium.

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Mixed Cut

Like many fine rubies, this example is fashioned as a mixed cut.

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Calcite Matrix

These exceptional ruby crystals on calcite are from Mogok, Myanmar.

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Origin In Marble

The snow white calcite matrix hints at the ruby crystal’s origin in marble.

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Ruby Crystal

The characteristic form of this ruby crystal allows it to be recognized.

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Buyer's Guide

Ruby can command the highest prices of any colored gemstone. The per-carat prices of fine-quality rubies have been rising consistently, many times breaking auction records.


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What To Look For

Ruby Ring and Pendant
Color Is The Most Important Quality Factor For Ruby

The finest ruby has a pure, vibrant red to slightly purplish red color. As the color becomes too orangy or more purplish, the ruby moves down in quality. The highest-quality rubies have vivid color saturation. The color must be neither too dark nor too light to be considered finest quality.

11.01-carat Ruby
Clarity Refers To The Inclusions

People in the trade expect rubies to have at least some inclusions because inclusion-free rubies are rare. Ruby value depends on how visible the inclusions are. Obvious inclusions or inclusions that reduce transparency or brightness lower a ruby’s value dramatically.

Various Cuts of Rubies
Cut Is One Of The Most Important Factors In Appearance

Several factors affect the cut and proportion of rubies on the market. A ruby’s crystal shape dictates its suitability for certain cuts. The most common shape is a flat tabular hexagonal shape, but ruby crystals from some sources can be elongated.

Rubies from Myanmar
Carat Weight Allows For Precise Measurements

Fine-quality rubies over one carat are very rare, but commercial-quality rubies are commonly available in a wide range of sizes. The price per carat goes up significantly for ruby as it increases in size.

Ruby Quality Factors: The Comprehensive Guide

Tips & Advice

1. Work with a jeweler you trust.

Judging the quality of ruby requires expertise. Look for gemological credentials. A jeweler who knows and loves ruby will have several to show you so you can see quality differences side by side.

2. Don't confuse origin with quality.

Even the best mines produce low-quality material. Where a ruby comes from is no guarantee of value or quality. Fine-quality rubies can come today from several countries.

3. Ask about treatment.

Most ruby has been heated, and some gems on the market also have had color diffused into the surface or fractures filled with lead glass to improve their appearance. When shopping, ask about treatment information included in writing.

4. When in doubt, get a lab report.

A report from an independent laboratory like GIA can confirm that the ruby you are buying is natural and tell you whether there is evidence of treatment.