The ruby is considered one of the four precious stones, with the others being the sapphire, the emerald and the diamond. Ruby is red corundum, while all other color conundrum varieties are considered to be sapphires. Essentially, rubies are red sapphires, because they are identical in all properties except for color. Rubies are one of the most expensive gemstones with large rubies being rarer than comparable diamonds.
Hardness: Ruby has a hardness of nine on the Mohs scale of hardness.
Color: In a ruby, the primary hue must be red. All other hues of the gem species corundum are considered to be sapphires. Ruby may exhibit a range of secondary hues such as orange, purple, violet and pink. The highest quality rubies are a vivid medium-dark toned red.
Birthstone: The ruby is the birthstone for those who are born in July. On the Zodiac chart, ruby is the stone for Capricorn. Ruby is also used to celebrate a couple’s fifteenth and fortieth wedding anniversary.
Scarcity: For a ruby to be produced in the natural environment, a perfect combination of aluminum oxide, correct temperature, correct pressure in the earth’s crust and very low silicon content is a required. This makes rubies very rare.
Value: The color of ruby primarily determines its value. Pigeon blood-red, the brightest and most valuable shade commands the largest price. Clarity is the second most important determinate of value for a ruby. Similar to the diamond, a clear ruby will obtain a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone is not in its natural form. Cut and weight are also important factors in determining the price.
Most Common Cuts: Rubies are a versatile stone. Transparent rubies are cut in step and in a brilliant cut. Rubies that show a 3-point or 6-point star are often cut into cabochons to display this effect.
Chemical Formula: The chemical formula for a ruby is Al2O3:Cr.
Synthetic Varieties: All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles called “silk”. Gemologists study these inclusions in natural rubies to discriminate them from synthetics or substitutes. Most rubies today are treated in some form, with heat treatment being the most common. Some stones are mistaken for rubies, such as the pink sapphire, red spinel and red garnet.
History: Rubies are steeped deeply in history and have been a prized gemstone for thousands of years. Its history is recorded in ancient Sanskrit writings and it is mentioned in the Bible. In Sanskrit, ruby is called ratnaraj, or “king of precious stones.” In the Bible, only wisdom and virtuous women are “more precious than rubies.” Rubies have adorned many royal castles with their fiery brilliance. The crown of Charles IV of Luxembourg held a huge ruby that was 250 carats.
For centuries, the Mogok Valley in Burma was the world’s main source of rubies. Although that area produced some of the finest rubies for quite a long time, in recent years very few quality rubies have been found there. This easily explains why England took the rather drastic step of invading and annexing Upper Burma in 1885 when it learned a French company would begin mining there. During the 1990s, central Myanmar became the world’s main ruby mining area. Rubies have also been mined in Thailand, Cambodia, India, Afghanistan, Vietnam, Tanzania, and Mozambique. Other sources of ruby include Pakistan, Tajikstan, Australia, and the United States. Recently, large deposits of rubies were found under the receding ice shelf of Greenland.
Rumored Healing Properties: The healing powers of gems remain a controversial issue, but healers have touted their power for centuries. There are many beliefs and legends about the ruby. Many consider rubies a symbol of love and passion. It is believed that the person who possesses a good-quality ruby will live a life of peace and harmony. One who wears the stone was thought to be protected against all harm, and would be blessed with good health. Rubies are said to enhance ones status and bestow fame, virtue, warmth and power to its wearer. They are also said to increase concentration.
Physically, they are also believed to treat depression, peptic ulcers, fevers, rheumatisms, backache, anemia, toenail problems and gout.