Compare A Yellow Sapphire To The Blue

A sapphire, like a ruby, is made of corundum. Because sapphires have traces of iron and titanium, most have a blue hue; however, sapphires also come in yellow, pink, purple and green. There are many factors to consider when comparing the traditional blue sapphire with the more unusual yellow-shaded stones.

Instructions

1. Understand the physical properties of a sapphire. All sapphires -- blue and yellow included -- have a nine on the Mohs hardness scale. These gems also share a specific gravity of 3.99 to 4.00 and a refractive index of 1.76 to 1.78, similar to a diamond.

2. Evaluate the different sizes. Both shades of sapphire can be found in smaller sizes, but only blue sapphires are found in larger sizes up to 10 carats. Yellow sapphires are usually found in sizes no larger than three carats.

3. Learn about different cuts for sapphires. Sapphires --whether blue or yellow -- can come in multiple shapes, such as Princess Diana's iconic oval-shaped engagement ring, but can also have a cushion cut or a round brilliant cut.

4. Understand how blue and yellow diamonds get their color. Blue diamonds -- of which cornflower blue is the most sought-after and valuable shade -- get their color from equal, but trace, amounts of titanium and iron in the corundum. Yellow diamonds get their color from the present of iron and the absence of titanium.

5. Ask if the sapphires you are looking at have had their colors enhanced. Up to 90 percent of sapphires have been heat-treated in order to intensify their color. A heat-treated sapphire is not as valuable as one with its natural color intact.

6. Know the different geographical origins of blue and yellow sapphires. While some of the world's most brilliant blue sapphires are mined in Montana and Kashmir, yellow sapphires are mined in Sri Lanka. The different geographical origins of these gems is due to the different mineral composition of the soils in which they were formed.

7. Learn about the different astrological interpretations of these sapphires. Blue sapphires represents the powers of the Roman god Saturn, while yellow sapphires are considered to be ruled by the god Jupiter. Blue sapphires is said to make a person well-balanced and motivated; astrologists claim yellow sapphires can make a woman more marriageable.

8. Evaluate the price ranges for sapphires. Yellow diamonds are sold for $100 to $300 per carat. Blue diamonds -- especially those with a cornflower blue hue -- can sell for $250 up to $5,000 a carat.

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