All About Ruby
Ruby is distinguished by its bright red color. This gemstone is most desirable because of its hardness, durability, lustre, and rarity. Ruby is the red variety of the mineral Corundum. Sapphire is the other gem variety of the Corundum family; encompassing all colours of Corundum aside from red. In essence, Ruby is a red sapphire. The reason why it is classified as an individual gemstone is because of its special allure and historical significance.
The colour of Ruby ranges from bright red to dark reddish-brown. The most preferred colour is a deep blood red with a slightly bluish hue. Ruby with this colour property is known as “Burmese Ruby” or “Pigeon Blood Ruby”. Ruby from Burma is famous for its exceptional colouring, but it’s very difficult to find one with a significant carat value. Large Burmese Ruby can be worth millions of dollars.
Many Rubies on the market today are from Thailand. Rubies from Thailand have a less-desirable brownish hue. They often can be heat treated to improve colour. Heat treating a Ruby can also increase its transparency by removing internal flaws.
Inclusions of tiny and slender parallel Rutile needles in Ruby cause a polished gem to exhibit asterism. A Ruby exhibiting asterism is known as star Ruby. Star Ruby exists with six ray stars, though twelve ray stars are known. Rubies must have good transparency to possess gem value.
Although Ruby can be one of the most expensive gemstones, it also comes in more dull opaque forms that are fairly inexpensive. These are usually polished into cabochons.
The color of Ruby is caused by minute inclusions of the metal chromium. These impurities are often responsible for causing a Ruby to fluorescent. Rubies also display a lighter more intense colour when viewed at different angles. This effect is known as pleochroic.
Ruby was first synthesized in 1902. The process of creating synthetic Ruby is known as the Vernueli process. Only experts can distinguish between natural and synthetic.
Large Ruby gems are extremely rare and valuable. Fine coloured Ruby with a deep red colour and excellent transparency can reach several thousands of dollars a carat. Synthetic Rubies are inexpensive and often used as a cheap substitute for natural Rubies.
Variety of Ruby
- Burma Ruby
- Ruby Fuschite
- Ruby Zoisite
- Star Ruby
False Named Ruby
Many deceitful names are given to less valuable red gems in connotation with Ruby. Many of these names are used by unscrupulous dealers to confuse inexperienced buyers. Generally speaking, any time the word Ruby is used with a prefix (except for those outlined above), it is a fake or a less valuable red gemstone. The red Garnet gemstone Pyrope is particularly vulnerable to be called Ruby with a tacky prefix.
Ruby Treatments and Enhancements
Rubies are often heat treated to improve colour as well as burn out certain inclusions. It is common industry practice to treat Rubies, and untreated Rubies with very few flaws can be exceptionally valuable.
A recent practice in the gemstone industry is to fracture-fill Rubies to conceal flaws. This is done by heat treating them in molten lead glass. Fracture-filled rubies are significantly cheaper than their counterpart, and because of this one should only buy Ruby from a reputable dealer.
Gemstones Similar to Ruby
Ruby is identical in appearance to Ruby Spinel. Ruby and Spinel often occur together in the same mineral environment and localities. Garnet and red Tourmaline (Rubellite) may also resemble Ruby, though Ruby is significantly harder.