How can you tell the quality of a ruby?

Portrait for the Coronation of Queen Victoria by George Hayter (detail), wearing the new Imperial State Crown made for her by the Crown Jewellers Rundell and Bridge, with 3093 gems, with the Black Prince’s Ruby at the front. (Public Domain photo)

Many cultures have considered rubies the gemstone of kings. Historically, the stone was worn in many battles as it was thought to be a stone of protection.  Some cultures even went as far as inserting the stone into the skin as they believed this would protect them. Ruby goes back as far as the Bible and is still ever so popular. With its intense red color it only makes sense that it also symbolizes wealth and passion. It is the birthstone of July and Cancer and both the 15th and 40th anniversary stone.

As one of the world’s most popular gems, many ask what makes a ruby so beautiful and how does one tell if the ruby they are looking at is of high quality? This is a great question! You don’t need to be a gemologist to understand the quality and value of a ruby, but we all might benefit from more education shopping for rubies.

Historically, all red stones were called rubies from the Latin word, ruber or “red”. It wasn’t until ruby was identified as corundum did it separate them from other luscious red stones. You may have heard of the the famous 14th century Black Prince’s Ruby in the British Imperial Crown. Well, this “ruby” is actually a red spinel and was thought to be a ruby until the 1940’s.

What is a Ruby?

Ruby is a variety of the mineral corundum that contains chromium, a rare element that imparts the red color and fluorescence. Both ruby and sapphire are corundum, just with different colors. Gem-quality red corundum is considered ruby, while all other colors of gem-quality corundum, including colorless, are sapphire. Since sapphire can also be found in the “ruby” color, there can be a very fine and subjective line between pink sapphires and red rubies.  In a fascinating article, Richard Hughes observes that before the 20th century, pink was considered a “light red” and some rubies were indeed described as “pink rubies.” Over the course of the 20th century, “someone decided that pink was not red,” and the first references to pink sapphires appeared. The mineral corundum forms in metamorphosed crystalline limestones and dolomites, as well as other metamorphic rock types such as gneiss and schist. It also occurs in igneous rocks, such as granite and nepheline syenite.

Where Do Rubies Comes From?

Ruby from the island now known as Sri Lanka has been mined since 543 BC & ever since. It may be the  first ruby to appear in Europe in Etruscan jewelry. What is now known as Myanmar (until recently, Burma) has been a primary source of fine ruby for somewhat longer, since 600 BC. Recent political turmoil has severely limited availability from this historic source.  As an oxide of aluminum & often a byproduct of aluminum mining, ruby is found through Asia. Recent discoveries in Mozambique & Madagascar have become principal sites for exceptional ruby but reserves are likely to be limited. 

Are there Different Grades of Ruby?
Many are familiar with the 4 c’s of grading diamonds, and they want to know if rubies are graded similarly. Most rubies do not come with a grading report; however, like a diamond, color, clarity and size are significant in pricing. The most important of these factors is vividness of color. The finest ruby has a pure, vibrant red. Gemologists assess color by considering huetone, and saturation. Gemstones often have a secondary hue in addition to a primary hue. In red gemstones, the most common secondary hues are purple and orange. Connoisseurs consider a pure red or red with just a hint of purple to be the top quality in red gems. As the hue moves further from this ideal, value drops. That doesn’t mean that purple reds and orange reds aren’t beautiful in their own right. In fact, few gems approach the ideal red. Clarity grades are less important in red gemstones than in colorless gems such as a diamond. That’s because the darker color helps to hide imperfections in the stone. In addition, eye-visible inclusions near the center of the gem will be more noticeable than those toward the sides. Among the rarest gems in the world, most rubies undergo heat treatment to improve their color — and increase their value.

 

How Much is a Ruby Worth?

Ruby can command the highest prices of any colored gemstone. Per-carat prices of fine-quality rubies have been rising consistently, many times breaking auction records. For better-quality material, slight differences in color can make significant differences in value. For top-color ruby that’s also free of eye-visible inclusions, the price rises even more. The per-carat price of ruby can also increase dramatically as size increases, especially for better-quality stones. And finally, fine-quality rubies over one carat are very rare and also increase the price. The per carat price of a ruby is usually about the same as a diamond.

 

How to Care for your Ruby

Warm soapy water is always safe. Ultrasonic and steam cleaners are usually safe for untreated, heat-treated, and lattice diffusion treated stones. Fracture-filled, cavity-filled, or dyed material should only be cleaned with a damp cloth. Since many of these treatments are unknown to most wearers, we suggest the safe route, just a little warm soap and water with a soft bristle toothbrush. And of course one of the safest methods, just bring it in to Argo & Lehne Jewelers for us to not only clean your stone but to also check to security of the stone. This is always complimentary and our pleasure.

 

Why I/We Love Rubies

Truly, there was a time that I actually didn’t love rubies, but that was when I was seeing less than desirable rubies without the depth and color of a high quality ruby. You know the ones, often seen in a department store. Working at Argo & Lehne Jewelers, I fell head over heels for the stone. I love the brilliant reds, and add a contrast of diamond and I am completely weak in the knees. So, here are just a few of my favorites in stock now. To see all of our in-stock ruby pieces, click on this link. 

I love this necklace because it’s proof that a small ruby with diamonds can still make a great impact. Plus, at an approachable price, $980, this makes an excellent stand alone or stacking necklace.

 

This is an Argo favorite. High-quality rubies, an everyday piece that wows. When in doubt, this is always a yes!

For the person who loves rare and one of a kind pieces, this is a star ruby center with gorgeous calibre cut rubies flanking the stone and in a beautiful vintage Art Deco ring. A true conversation piece. Warning: expect attention!

This beauty I recently spotted in a jewelry industry magazine and had to procure it. The unusually cut Burmese ruby flush set in a simple dome shaped ring is so subtle with just the right splash of that juicy gem we just can’t get enough of! You have to see this one up close and in person.

When searching for the perfect ruby, it is always best to buy from a store with an American Gem Society gem lab & certified gemologist to be clear you are getting the ruby you want, heated/unheated, treated/natural or lab grown. I hope you enjoyed learning about rubies as much as I did. Thanks for reading. – A&L President, Michelle Ward