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Rubies

The ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum. The red color caused mainly by the presence of the element chromium. Its name comes from ruber Latin for red. Other varieties of gem-quality corundum called sapphires. The ruby considered one of the four precious stones, together with the sapphire, the emerald, and the diamond. All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as silk. Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, simulants, or substitutes. Usually the rough stone heated before cutting. Almost all rubies today treated in some form, with heat treatment being the most common practice. However, rubies that are completely untreated but still of excellent quality command a large premium. The Price of rubies primarily is by color. The brightest and most valuable red called pigeon blood red, commands a huge premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone been treated. Cut and carat also determine the price. In the evaluation of colored gemstones, color is the single most important factor. Color divides into three components, hue, saturation and tone. Hue refers to color as we normally use the term. Transparent gemstones occur in the following hues: red, orange, yellow, green, blue, violet, purple and pink are the spectral hues. The first six are spectral hues; the last two are modified spectral hues. Purple is a hue that falls halfway between red and blue. Pink is a paler shade of red. In nature there are rarely pure hues so when speaking of the hue of a gemstone we speak of primary and secondary and sometimes tertiary hues. In ruby the primary hue must be red. All other hues of the gem species corundum called sapphire. Ruby may exhibit a range of secondary hues. Orange, purple, violet and pink are possible.