The value of a diamond is determined by the Four Cs: Cut, Color, Clarity and Carat weight.
I1-I2-I3 (Imperfect): Inclusions visible to the unaided eye
Carat is the standard unit of measurement used to determine a diamond’s weight. One carat consists of 100 points, so a 50-point diamond equals a half carat, or 0.50ct. It is important to remember that although two diamonds may have the same carat weight, their color and clarity may be different, thus determining each individual stone’s value. Additionally, since larger diamonds are more rare than smaller diamonds, diamond value tends to rise exponentially with carat weight. A 2.00ct diamond is more valuable than two 1.00ct diamonds.
More About Diamonds
The most precious of all gems, diamonds have an incredible rarity factor. It takes a minimum of one million diamonds to be mined in order to find a 1.00ct gem-quality diamond, so each 1.00ct quality diamond is literally one in a million. Making them even more incredible, the mining of diamonds requires moving and sifting 250 tons of the Earth’s crust to find just one diamond. Mining companies literally move mountains to find diamonds.
Diamonds have the longest endurance of any substance known on Earth. Carbon dating has established that diamonds, on the average, are 3.4 billion years of age. They consist of pure carbon and there is no chemical difference between them and carbon powder (the lead pencil center). Obviously, however, the physical difference between carbon powder and a diamond is fascinating. Diamonds are created from a basketball-sized piece of pure carbon that becomes white-hot. It is squeezed to the size of a small pearl, turning from black to clear in the process and becoming the hardest material known to humans, ranking a 10.0 on the Mohs Scale . Because they are so hard, diamonds can only be ground and polished by using diamond dust that has been ground from other diamonds.
Diamonds are found in a rainbow of colors. The value of a fancy-colored stone depends largely on the rarity of its color (reds and greens are rarer than yellows and browns), the saturation of the color (from faint to vivid), and the purity of the color (whether it is bright and clear or clouded by other underlying colors). Probably the most famous colored diamond is the Hope, which features a deep-blue color and weighs an amazing 45.52ct. It can be seen at the Smithsonian Institute in Washington, D.C.
With diamonds found all over the world, America has a couple small producing diamonds mines, but it only produces industrial grades with non-gem grade material. These black and brown industrial-grade diamonds are widely used as cutting and grinding tools in various industries, such as oil drilling and stone carving.
Diamonds have come to symbolize the ultimate gift of love and romance and, in the United States, are traditionally used in engagement and wedding rings. The tradition of the diamond solitaire engagement ring may have started in 1477, when the Archduke of Austria gave a large solitaire diamond to Mary of Burgundy for her hand in marriage. Amidst this tradition of romance, the diamond is also the birthstone for April and given as 10th, 30th, 60th and 75th anniversary gifts.
Diamonds have been the pride of empires throughout time. Ancient Hindu followers believed diamonds were created by thunderbolts striking the ground. Ancient Greeks believed that diamonds were teardrops of the gods and splinters of stars that had fallen to Earth. The stones were believed to possess magical qualities and have powers far beyond the understanding of common man. Even the name stems from “adamas,” the Greek word for “unconquerable” and “indestructible.”
The diamond is considered the most magical of all gems. When worn, it promotes spirituality, even ecstasy, and is often utilized in meditation. The diamond promotes self-confidence in relations with the opposite sex and is often worn to conquer infertility. The diamond is the stone of love and is worn to ensure fidelity. Owing to its sparkling and flashing nature, it has long been regarded as a stone of protection and peace. It can be worn today for courage and strength, and represents fearlessness and invincibility.
Since only diamonds can scratch other diamonds, it is important to wrap and store your diamond jewelry pieces separately so they do not touch one another. To clean jewelry at home, soak diamonds in warm, sudsy water made with any mild liquid detergent. Brush with a soft toothbrush and rinse and pat dry with a soft, lint-free cloth. Other effective cleaning methods include soaking diamonds in household ammonia, brand-name liquid jewelry cleaners, or even a glass of vodka.
Known for its fiery combination of colors, opal is called the “Cupid stone” because it was said to reflect the complexion of the Greek god of love. The ancient Romans believed the gem was the symbol of hope, good luck and purity. Today, it remains a symbol of hope and inspiration. With a name stemming from the Latin word for “precious stone,” opal is considered October’s birthstone and is traditionally given as a 14th anniversary gift.
Opals are luminous and iridescent stones with inclusions of many colors called "fire." It is sometimes called the "queen of gems" because it can flash patterns of color representing every hue of the rainbow. In fact, most stones are usually cut into domed cabochons to enhance the color play. The brilliance and pattern of an opal’s fire determines its value. Opals with strong flashes of red fire are generally the most prized, while stones with blue or green flashes are more common and subsequently less valuable. Stone size also helps determine price, since the gem is very rare in larger sizes.
In order to produce a stone that is less expensive than a solid opal, an opal doublet can be manufactured. It is composed of a thin layer of opal glued on top of another mineral (usually a black onyx or ironstone, which enhances the opal's color). An opal triplet can be made with a thin layer of opal sandwiched between a layer of clear quartz on top and a layer of obsidian or ironstone on the bottom. The clear quartz top layer makes the gem harder and less susceptible to scratches. Since top-quality natural opals are extremely rare and expensive, many are treated with colorless oil, wax or resin to enhance their appearance. Ranking a hardness of 5.5-6.5 on the Mohs Scale, these treatments also fill cracks in the stone to improve durability.
A species of quartz, opal is one of the few gemstones that are sedimentary in origin. Millions of years ago, after ancient seas receded, silica-laden sediment was deposited around shorelines. Erosion made much of this silica into a solution that filled cracks in rocks, clay and fossils. Layers upon layers of silica jell were added to each other over millions of years and became precious opals. The stones still contain 6 to 10 percent water, a remnant of ancient seas. Because they have high water content, opals should be protected from heat and strong light in order to prevent them from drying out and cracking.
Opal is found in a range of hues, including white opal (the most common), black opal (the most valuable), boulder opal (black opal with iron oxide), crystal or water opal (which is transparent), and fire opal (which features a bright solid color). Prices can vary from a few dollars per carat for white opal to more than $1,000 per carat for fine black opal.
White opals tend to have more diffused fire due to their light background color. Rare black opals have a black to dark gray body color that allows for the fire to be the most noticeable, making them the most valuable type of opal. Boulder opals are cut with the natural host rock left on the back. They are found with interesting hills and valleys on the surface and inclusions in the foreground, forming odd shapes that make them a designer’s delight. Crystal opal is transparent with flashes of rainbow colors, while fire opal only occasionally has this play of color.
Fire opal’s backdrop color is the main attraction. It has recently become very popular as jewelry designers are growing to appreciate its bold presence and bright color. With hot yellows, fiery oranges and juicy reds, the fire opal is a bright gemstone that is usually faceted to add sparkle and enhance the fabulous color.
The relatively rare Peruvian blue opal comes from the Andes Mountains in Peru and was cherished by the Incas. It features the translucent turquoise-blue color of tropical oceans and has soft, relaxing energies said to be good for quieting the mind during meditation. It is thought to relieve stress and bring about a tranquil, healing nature. Peruvian blue opal is also believed to increase clear thinking, spark creativity and aid in sleep.
The vast majority of the world's opal supply comes from Australia, first discovered there by gold panners in 1863. In addition to the small quantity of opal produced in Kenya and Canada, white opal is mined in Brazil, black opal is found only at Lightning Ridge in Australia, and crystal and fire opal can be found in the United States and Mexico.
Opals have been treasured for thousands of years throughout the world. A beautiful opal called the “orphanus” was featured in the crown of the Holy Roman Emperor and was said to guard the regal honor. The Aztecs mined opal in South and Central America and Archaeologist Louis Leakey found 6,000-year-old opal artifacts in a cave in Kenya. Napoleon gave Josephine a beautiful opal with brilliant red flashes called “The Burning of Troy,” making her his Helen. To this day, opals are still set in the crown jewels of France.
Shakespeare regarded opal as a symbol of shifting inconstancy, comparing its play of color to play of mind. In “Twelfth Night” he wrote, “Now the melancholy God protect thee, and the tailor make thy garments of changeable taffeta, for thy mind is opal.” In the 19th century, Sir Walter Scott caused a reputation that opals were unlucky. The heroine of his popular novel had her life force caught in the opal she wore in her hair and died when its fire was extinguished.
For thousands of years, opals have been revered for their supposed mystical powers. Romans thought the stone kept the wearer safe from disease and wore it near the heart to ward off evil and protect travelers. Ancient Arabs believed that opals fell from heaven in flashes of lightning, which explained their fiery colors. During the Middle Ages, opal was called “ophthalmios,” meaning “eye stone,” due to a widespread belief that it was beneficial to eyesight. Some thought its effect on sight could render the wearer invisible, and the stone was even recommended for thieves. In medieval Scandinavia, blonde women wore opals in their hair to prevent it from going gray.
Today, opals are still believed to hold magical powers. White opals, when used in rituals on a full moon night, are said to bring the moon goddess’ powers into full effect within the practitioner. A fire opal surrounded with 10 or 12 diamonds and worn on a gold necklace is said to have excellent money-drawing power.
Opals have been said to bring good luck, grant vigor and ideally protect travelers. The stones have long been believed to develop and increase mental capacities and open the unused powers of the mind. The colorful fire in opals is said to develop a more creative imagination and help recall past lives. It is believed that the most magically powerful opals come from Lightning Ridge in Australia and that the gem loses its power once its owner dies.