The July Birthstone is Ruby

The characteristics of Ruby

Rubies are known to display fluorescence, of a mild glowing effect after the gem has been targeted with direct illumination by ultraviolet light. This effect is a result of the presence of chromium inclusions, the same element giving Rubies their iconic red color. Pleochroism has also been noted in Rubies, where two or more different colors are visible when viewing the gemstone at different angles.

Cut and Clarity for the July birthstone

Rubies are expected to have at least minor inclusions, though it is preferred to have minimal. You’ll find Rubies cut into multiple shapes, though the crystal formations are highly suited for flat hexagonal cuts such as oval and cushion. The crown of Rubies is typically brilliant cut while the facets are triangular or in a kite shape. It’s also common to find step cuts with rows of square or otherwise rectangular faceting. Other classic shapes include round, triangle, emerald cut, pear and marquise though these are typically found in smaller sizes if high quality. Large carats are typically uncommon in fine-quality varieties. If high-grade Rubies are found in large carat amounts, expense skyrockets and has broken auction records.

The value of Ruby

The deeper the color of a Ruby, the higher quality the gemstone is. A large transparent Ruby is rarer than even diamonds. The more transparent the gem is, the higher the quality is. While inclusions are typically a deterrent of value, some rubies exhibit asterism due to slender needle-like inclusions of rutile. Polished Rubies with asterism and high enough transparency to clearly see the star-like reflection are highly valued.

Is Ruby ever treated?

Rubies with less than desirable color such as brownish tones are often heat treated to improve color. The process of heat treating also increases the transparency of the gem by eliminating some tiny internal flaws. While heating is the most common method of treatment, it is also not entirely uncommon to find mildly dyed Rubies in the jewelry industry. Fracture-filling and cavity-filling can also be found as a treatment for Rubies though these tend to be considered far less valuable.

More about Ruby the July birthstone

Rubies are an incredibly hardy gemstone and do not exhibit a tendency of breaking if struck, also known as cleavage. This makes Rubies a favorite choice for rings since the gem stands up to daily wear.

While Rubies are only bested on the hardness scale by diamonds, the gem is still capable of chipping or fracturing internally. Especially gems fracture filled or dyed are susceptible to basic acids, even lemon juice.

The best method for cleaning Rubies is to use warm soapy water. Steam cleaners and ultrasonic cleaners tend to be safe as well, unless the gem has been fracture filled or dyed as the cleaning process may remove the treatment or exacerbate inclusions.

The American Gem Society's July Birthstone page has more information to help you buy from knowledgeable and skilled jewelers and to help you make the most informed buying decision.