July Birthstone
Ruby
"Passion, protection, prosperity, and vitality"
About Ruby
Chemical Formula
Al₂O₃ + Cr (corundum with chromium)
Crystal System
Trigonal
Hardness
9 on Mohs scale
Color
Red
Primary Origins
Myanmar (Burma), Mozambique, Thailand, Sri Lanka, Afghanistan
Ruby is the king of colored gemstones — that is not marketing copy; it is what the ancient Hindus actually called it (ratnaraj: king of precious stones). For over two thousand years, across cultures that had no connection with each other, ruby was understood to contain something exceptional: a fire, a life force, a protection. The Burmese warriors who surgically implanted rubies in their skin before battle were doing something that strikes us as superstition but that reflects a deep and consistent human intuition that this particular red stone carries vital power. The color is everything. Ruby's red comes from chromium — the same element that makes emerald green — and what chromium does to corundum is remarkable: it not only produces the deep red color but also creates a fluorescence that makes the finest rubies literally glow in sunlight, as if the fire really is inside the stone. The finest rubies in the world come from Myanmar's Mogok Valley and have done so for over five centuries. The specific quality of color — "pigeon's blood red," a deeply saturated red with a slight blue overtone and strong fluorescence — is so associated with Mogok that it has become the gold standard for the entire gem category. The 2015 Sunrise Ruby, a 25.59-carat Mogok stone, sold for $30.3 million, making it the most expensive colored gemstone per carat ever sold at auction. July birthdays carry a stone that has been the symbol of passion, royalty, and vital force longer than almost any other gem. Whether that fire comes from the chromium or from somewhere else, the effect is the same.
History
Ruby has been prized in Asian cultures for at least 2,000 years. The Sanskrit word for ruby, ratnaraj, means "king of precious stones." Burmese warriors historically implanted rubies under their skin believing they would make them invincible in battle [Kunz, G.F., 1913. The Curious Lore of Precious Stones]. The Mogok Valley in Burma (now Myanmar) produced the finest rubies in the world for over five centuries — the "pigeon's blood" rubies, deep red with a slight blue fluorescence, are considered the most valuable colored gemstones per carat of any gem. The British Crown Jewels include several notable Burmese rubies.
Mythology & Cultural Traditions
The ancient Hindus called ruby ratnaraj and believed it contained a flame that could not be extinguished — a reflection of the god of fire burning inside the stone. In ancient Sanskrit texts, the ruby was associated with the sun and was believed to protect its wearer from enemies and illness. Medieval European astrologers connected ruby to Mars, the planet of war, and believed it could predict misfortune by darkening in color. The Bible mentions ruby in Proverbs 3:15 ("She is more precious than rubies") and in descriptions of the High Priest's breastplate.
Geology & Formation
Ruby is red corundum — aluminum oxide colored by trace amounts of chromium. The same mineral without color-causing impurities is white sapphire; with iron and titanium, it becomes blue sapphire. Chromium both causes the red color and creates the characteristic red fluorescence that makes the finest rubies glow under ultraviolet light. The world's finest rubies — from Myanmar's Mogok Valley — are remarkable for their "pigeon's blood" color (a specific deep red with blue overtones) and their strong fluorescence. [Source: GIA Gem Encyclopedia, gia.edu; Mindat.org]
Famous Rubys
The Sunrise Ruby
A 25.59-carat Burmese ruby that sold at Sotheby's Geneva in 2015 for $30.3 million — at $1.18 million per carat, the most expensive colored gemstone ever sold at auction.
The DeLong Star Ruby
A 100.32-carat cabochon ruby from Burma displaying a perfect six-pointed star (asterism), now at the American Museum of Natural History in New York.
Did You Know?
The most expensive colored gemstone ever sold at auction was a ruby — the Sunrise Ruby at $30.3 million ($1.18 million per carat) in 2015.
Ruby and sapphire are both varieties of the mineral corundum; the only difference is color. Every corundum that is red is a ruby; every other color is sapphire.
Some rubies display asterism — a six-pointed star visible on the surface of cabochon-cut stones — caused by intersecting needle-like inclusions of rutile.
Care Instructions
Ruby is one of the hardest gems (Mohs 9) and is generally durable. Clean with warm soapy water and a soft brush, or in an ultrasonic cleaner for untreated stones. Avoid steam cleaners for fracture-filled rubies. Natural rubies almost always contain inclusions — extreme clarity in a large ruby should raise authenticity questions. [GIA, gia.edu]
Frequently Asked Questions
What is the birthstone for July?
The primary birthstone for July is Ruby.
What color is Ruby?
Ruby is Red. Its chemical formula is Al₂O₃ + Cr (corundum with chromium).
What does Ruby symbolize?
Ruby symbolizes Passion, protection, prosperity, and vitality.
How hard is Ruby?
Ruby rates 9 on Mohs scale on the Mohs scale.
Where is Ruby found?
Ruby is primarily found in Myanmar (Burma), Mozambique, Thailand, Sri Lanka, Afghanistan.
How should I care for Ruby jewelry?
Ruby is one of the hardest gems (Mohs 9) and is generally durable. Clean with warm soapy water and a soft brush, or in an ultrasonic cleaner for untreated stones. Avoid steam cleaners for fracture-filled rubies. Natural rubies almost always contain inclusions — extreme clarity in a large ruby should raise authenticity questions. [GIA, gia.edu]
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