You are invited to the

Fall 2024 Gemstone Roundtable

You are invited to the

Fall 2024 Gemstone Roundtable

Rubies: The Traditional Birthstone for July

Today, most of us in the West don’t impart gemstones with any real symbolic value—except for connecting a birth month with a “birthstone,” or associating diamonds with nuptial commitments (the latter connection, “A Diamond is Forever,” was created by De Beers in 1947). In many world cosmologies, however, the ruby is far more than just a pretty stone. The word ruby comes from ruber, the Latin word for red—the color of war, love, and passion. In ancient India, ruby was called the “king of precious stones” for its rarity, hardness (second only to diamond), beauty, and seemingly mystical powers. Buddhists texts refer to rubies as the “sacred tears of the Buddha,” said to promote devotion, tranquility, happiness, and spiritual enlightenment. Burmese warriors believed that carrying a ruby into battle would make one invincible. Medieval Europeans asserted that rubies bestowed health, wisdom, wealth, and success in love.

One of the oldest recorded sources of fine rubies is the Mogok area of Myanmar (formerly known as Burma). Since the late 20th century, the Luc Yen region in northern Vietman has produced rubies of red to purplish-red colors. Mozambique is an important new source for rubies and some of the finds there have been compared to top-quality gems from Mogok. Other producers in the late 20th and early 21st centuries include Afghanistan, Pakistan, Sri Lanka, Kenya, Tanzania, and Madagascar.

Ring brooch, England, 1275-1300. Gold set with rubies and sapphires. Courtesy Victoria & Albert Museum, acc. 6808-1860
Pen box and utensils, Mugul empire, imperial workshops, 1650-1700. Nephrite jade set with rubies, diamonds, emeralds, and gold. Probably made as an emblem of office. Victoria & Albert Museum, acc. 02549(IS)
Ear plug, Nazira Assam, 19th century. Gold set with pale cabochon rubies in a lotus flower design. Victoria & Albert Museum, acc. 864.A-1907

Ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum. (All other varieties of gem-quality corundum are called sapphires.) The ruby’s color is due to the presence of the element chromium. The more chromium, the stronger the red.

All rubies have imperfections in them, including color impurities and needle-like inclusions known as silk. Gemologists use these inclusions to distinguish natural rubies from synthetics, simulants or substitutes. For example, before mineralogical testing was developed beginning in the late 18th century, red spinel, red garnet, and rubellite tourmaline were all mistaken for ruby (see our blog “Spinel: The Comeback Queen,” April 1, 2020).

Rubies are often heat-treated to remove purplish coloration and obtain a purer red. This process can also remove the silk, which may cause the gemstone to appear lighter in tone and more opaque. The gemstone trade generally accepts heat treatment as it is an irreversible treatment and does not alter its mineral structure. Some lower-quality stones have fractures and cavities that have been filled with lead glass to minimize the look of imperfections. Rubies that have been diffused or are glass filled are worth less than heat-treated examples. Before you purchase a ruby gemstone or ruby jewelry, ask if the ruby has been treated and by what method.

The quality and worth of a ruby is determined by its color, cut, clarity, and carat weight. The brightest and most saturated color is called “pigeon’s blood,” characterized by a deep, vivid red with a hint of purple; the color must be neither too dark nor too light. These are the finest of ruby stones and can command the highest prices of any gemstone. At least some inclusions are expected in gemstone-grade rubies, but the stone’s value depends on how visible these inclusions are. Where a ruby was mined does not automatically determine its value, because even the best mines produce low-quality material. If you’re in doubt, ask for a report from an independent laboratory like GIA (Gemological Institute of America) to determine if the ruby you are buying is natural and whether there is evidence of treatment.

Ruby is relatively hard (9 on the Mohs scale), and it has excellent toughness and no cleavage. These qualities make ruby a great choice for rings and other mountings subject to daily wear. Ruby is also resistant to the effects of heat and light. Note: fracture- or cavity-filled stones can be damaged by even mild acids like lemon juice. To clean ruby jewelry, warm soapy water is always safe. Only if the ruby is untreated or heat-treated, can it be subjected to ultrasonic or steam cleaners.

Whether your birthday is in July or you just want to treat yourself, owning a ruby is a rare joy. Visit llyn strong fine art jewelry to talk with llyn and her team about creating the perfect setting for either an heirloom stone or one selected for you by our graduate gemologist, Sydney Strong.

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