Interesting Ruby Facts and History

Everything You Need to Know About July's Birthstone

Facts about rubies
Getty Images / Dawid Wapenaar / EyeEm

Rubies are a fiery staple of the gemstone world. For centuries, rubies have been at the forefront of luxury and lore. What sets this stone apart from less prized gemstones is ruby's inherent beauty. But there's more to rubies than just a beautiful guise. Whether its biblical references or cases of mistaken identity, ruby is a gemstone you'll want to know more and more about. These interesting ruby facts will uncover some of the intrigues behind July's birthstone. 

Illustration of ruby facts
Illustration: The Spruce / Ran Zheng

What Is a Ruby and Where Are They Found?

Ruby is one of the four precious gemstones. The others are emerald, sapphire, and diamond. Ruby comes from the Latin "rubens" meaning red.

Rubies are made of corundum. Corundum comes in many other colors, but those colors are classified as sapphires. Pink corundum is sometimes referred to as pink sapphire and other times is referred to as pink ruby depending on the hue, region, and personal opinion. Ruby gets its red coloring from trace amounts of chromium. 

Ruby measures 9 on the Mohs Scale of Hardness, second only to diamond and matched with sapphire. This makes ruby an extremely hard and durable gemstone. 

History and Lore

Rubies symbolize power and protection. When worn as a talisman, ruby was believed to help protect warriors in battle. One more modern allusion to this legend is in The Wizard of Oz. Dorthy's ruby slippers were thought to protect her from evil. 

Rubies are referenced four different times in the bible. The Bible associates these gems with beauty and wisdom.  

According to ancient folklore, people of India believed rubies would help them be at peace with their enemies. 

Thailand is one of the leading hubs for ruby mining and production, with other leading countries including Madagascar, Sri Lanka, and India. 

Famous Rubies

Until the beginning of the 19th century, red spinels were thought to be rubies. Famous stones including "Black Prince's Ruby" and "Timur Ruby" were considered to be rubies until it was discovered that they and many other red stones were, in fact, red spinels. 

Some famous rubies include the "Rosser Reeves Star Ruby," the "Edwardes Ruby," and the "De Long Star Ruby"

In 2011, an 8.24-carat ruby ring belonging to Elizabeth Taylor and made by Van Cleef & Arpels sold at auction for $4.2 million, with the price per carat amounting to approximately $500,000. 

The most expensive ruby ever sold was the "Hope Ruby" which weighs 32.08 carats and sold for $6.74 million. 


High-quality rubies that weigh over 10 carats can sell for much more than a similar-sized diamond. Some large rubies have fetched sale prices upwards of $225,000 per carat. Comparably sized diamonds average a sales price of around $125,000 per carat. Rubies of this magnitude are significantly more rare than larger sized diamonds, which explains the difference in price.

The most desirable shade of ruby is a deep red with a hint of blue which is referred to as "pigeon's blood."

Inclusions (or imperfections) in rubies are to be expected and are generally well tolerated. However, when inclusions impact the transparency or brilliance of the stone, the value of the ruby dramatically decreases. 

Many top-quality rubies have been mined in Myanmar (formerly Burma), which is where the term "Burmese ruby" comes from.

Synthetic Rubies and Ruby Treatments

Like emeralds, almost all rubies have some type of imperfection, which helps in identifying synthetics. Synthetic rubies can be identified by its lack of inclusions. 

Simulated rubies were used in jewelry production since the 1850s. These are also known as garnet doublets, where a piece of garnet is fused with a pinkish-red piece of glass. This creates a gem that looks like a much more expensive ruby. Less expensive Victorian era jewelry incorporates these gems. 

 Synthetic "flame-fusion" rubies hit the commercial market in the late 1800s. Chemist Auguste Verneuil perfected this method and had his ruby material shown at the Paris World's Fair in 1900.  

Most modern rubies are treated to improve their color and durability. Treatments include heat treatment, irradiation, and fracture filling. All treatments should be disclosed to the buyer. 

The first-ever functional laser was created with a synthetic ruby crystal by Theodore H. Maiman in 1960. Synthetic rubies are used not only in laser technology but also in microelectronics.