One of the "Big 3" (Sapphire, Emerald and Ruby) ruby is the most valuable. Let's take closer at the King of Gems.
Ruby derives it's name from the Middle English: from Old French rubi, from medieval Latin rubinus, from the base of Latin rubeus ‘red. In ancient Sanskrit, ruby is called ratnaraj, or “king of precious stones.” In the Bible, only wisdom and virtuous women are “more precious than rubies.” Even diamonds were considered common in comparison to this fiery gemstone.
Rubies in History. Burma has been a significant ruby source since 600 AD. Records suggest that rubies were traded along China's North Silk Road as early as 200 BC. 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 Edwards Ruby, and the De Long Star Ruby.
In 2011, an 8.24-carat ruby ring belonging to Elizabeth Taylor sold at auction for $4.2 million, a carat price of $500,000! The most expensive ruby ever sold was the Hope Ruby owned by American heiress Lily Safra, which weighed 32.08 carats and sold for $6.74 million.
Location. Most ruby mines are found in Asia, in countries such as Myanmar (previously Burma and home to Burmese Rubies), Thailand, India, Pakistan, and Nepal. African mines include Mozambique, Mawali and Kenya. Other deposits can be found in Madagascar, Montana, China and Macedonia. rubies are also found in the US in the states of North Carolina, Montana, Wyoming, and South Carolina.
In 2017 a new deposit of ruby was discovered in Greenland near the town of Aappaluttoq. Providing the gemstone world with another conflict-free source of ruby. However the mine only has a projected life of 10 years.
Mining. Although rubies can be found in many locations, not all areas can be successfully mined. If deposits cannot be mined easily if they are located in remote, inhospitable, or politically volatile regions. Of if labor is too costly or if regulation presents obstacles. Theft, smuggling, and corruption take a toll on individual mining operations; but they can also affect market supplies or undermine consumer demand.
Mining is generally done is two ways:
Primary deposits-miners will build tunnels and drifts directly into the rock to retrieve the stones
Secondary deposits -most rubies are found this way, far from their original source. Usually alluvial deposits along rivers and streams.
Mineralogy. Rubies are a crystalline form of aluminum oxide or corundum. They are formed under extreme heat and pressure under the earth’s surface. The mineral corundum is made of dense oxygen and aluminum atoms packed inside it.
Color. Typically, the mineral is colorless, however, if the aluminum atoms are replaced by other substances, they can become other colors. They get their deep red from the chromium in their mineral composition. Chromium also gives the mineral its glowing fluorescence. Few rubies grow large enough to crystallize into fine gem material due to the coloring agent, chromium, since it also increases the chances of cracks and fissures. Colors can range from blood red (Pigeon's Blood), light red, pink, purple and orangey to brownish reds.
Cut. Ruby is most commonly cut round, oval, cushion and emerald shapes. Other shapes may be difficult to find in sizes above a carat. Cabochons are also a popular form.
Clarity. The industry recognized system of grading clarity:
VVS - Very, very slightly included - minor inclusions that can be seen under 10x magnification, but invisible to the naked eye. No effect on appearance.
VS - Very slightly included - noticeable inclusions sometimes visible to the unaided eye, and very easy to see under 10x magnification. Little to no effect on brilliance.
SI1 - Slightly included - large or numerous inclusions that can be easily seen under 10x magnification. These inclusions are apparent/very apparent with the naked eye. Slight effect on appearance, little to no effect on brilliance.
SI2 - Slightly included - obvious inclusions that can be easily seen under 10x magnification. Slight effect on appearance and brilliance.
I1 - Obvious inclusions - significant effect on appearance, brilliance and transparency
I2 - Prominent inclusions - significant effect on appearance, brilliance and transparency
I3 - Numerous and prominent inclusions - severe effect on appearance, brilliance and transparency.
About Star Rubies. A ruby is considered a Star Ruby when a three-point or six-point asterism, or star if you will, appears within the stone. This star is created when tiny fibers of rutile, also known as “silk,” have light reflected off of them in such a way that a star shape is formed. Star rubies are among the rarest and most coveted gems in the world.
Price. As of May 2015, the record price for a ruby is approximately $1.172 million per carat. ($30 million for a 25.59 carat Mogok “pigeon’s blood” ruby).
Fine quality rubies are some of the most expensive gemstones. The record price for a ruby is over $1,000,000 per carat! But due to the range of color and treatment (more than almost any other gemstone), prices can range from $100ct to thousands depending on clarity and color.
Star Ruby prices range from $100 ct to $4000ct.
Cabochons price range is $7 to $4500 per carat.
Treatments. The majority of the world’s rubies are subjected to heat treatment to improve their color. High temperatures maximize the purity and intensity of their red hue. Impurities may dissolve or become less noticeable after heating; however, heating will only improve the color if the gemstone contains the proper chemistry. If ruby shows no signs of heating, it is very rare and is a true treasure. The stone’s natural color must be confirmed by a laboratory report if it is to command a premium.
Another common treatment is glass filling or fracture filling. Fracture-filling is treating the ruby with colored, lead glass. This can improve not only the visible clarity but the color in certain instances. Note that the treatment has a caveat of not being durable, and can be damaged with cleaning in sonic jewelry cleaners. A more durable treatment is called flux filling. This material fills the cavities and allows the ruby to heal the fractures itself. Other treatment Beryllium Diffusion, oiling, and dying.
Care. 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. Source: GIA.
As always we strongly recommend your consult a reputable dealer when considering a gemstone purchase.
We recommend:
Comments