Zimagal Monthly Magazine - Volume One, Issue Ten

Sapphires and Rubies
Sapphire is the mineral corundum, which comes in every color of the rainbow, plus colorless. The most valuable variety of corundum is red, also known as Ruby. The name comes from the Latin rubrum, meaning "red." If the color is too pale, they are no longer called rubies but are pink sapphires; if more violet than red, they become violet sapphires. There are many variations in the color, and organizations such as the Gemological Institute of America has tried its best to come up with a system in that a corundum falling into a certain range of reds can be called a ruby.

Rubies
The highest quality, best colored, and most transparent rubies (usually from Burma), weighing from 3 to 5 carats, can be as valuable as diamonds, or more so. Very good rubies of greater weight are extremely rare and bring exceptional prices.

Rubies display something called pleochroism meaning that different colors, or variations of a color, appear in the same stone. When a ruby is tilted one direction, a bright red might be seen. When tilted in the opposite direction, a more carmine shade is visible. Rubies are also somewhat fluorescent, which makes them appear redder in sunlight.

Sapphires
Sapphires are usually thought of as being blue. Indeed, this is the most popular color of corundum. The blue can range from almost blackish greenish blue (cheap and unattractive; the type sold in many mall jewelry stores) to a light slightly violetish blue. The most valuable shade is a strong and vivid, but not too bright, pure blue.

Other Blue Stones
There are several other blue gemstones available, and should not be confused with sapphire: tanzanite, a variety of zoisite mined exclusively in Tanzania, always shows a hint of violet, is strongly pleochroic, and not as lustrous; cordierite (popularly known as iolite or "water sapphire") is a violet or gray blue; indicolite tourmaline is greenish blue, but a more vivid green than that of sapphire; blue zircon is electric blue, not unlike the color of blue topaz (heat-treated colorless topaz, in most cases - not blue in nature); blue spinel is often a cloudy blue.

Synthetics and Simulants
Sapphire has been imitated by such things cobalt blue glass and by glass-and-garnet doublets, also synthetic blue spinel. Synthetic blue sapphire has also been produced (ruby as well) for many years. In addition to imitation and lab-grown sapphires, genuine sapphires with low color have been subjected to heat treatment to improve the color.

Other Sapphire Colors
As you can see by the picture, sapphires come in orange and yellow and green and violet as well as blue. Colorless sapphire has been used as a substitute for diamond. These colored sapphires are far less valuable than blue sapphires and rubies. Pink sapphire is generally more expensive than the other colors, because it is such a lively, attractive stone. Green sapphire often comes in quite unappealing olive-y drab and dark muddy shades, but also in more attractive ones. Golden sapphire ranges from canary to brownish-yellow, like citrine. Violet sapphire, although attractive, is not widely appreciated. Although colors other than blue tend to be less valuable, there is a particular color - a vivid pinkish orange known as Padparascha - which commands high prices.