A Diamond weight is measured in a measurement known as carats, that is, each carat is a unit of measurement equal to 200 milligrams. Carat is not a measure of diamond size, but rather a measure of a diamonds weight. One carat can also be divided into 100 points.
For example, a .75 carat diamond is roughly the same as 75 points or 3/4 carat diamond.
Finding diamonds is rather difficult, as such, diamonds are pretty rare - thus, their increased value. For this reason, a 1 carat diamond will cost more than twice a 1/2 carat diamond - that is, assuming other characteristics are the same as the rarity increases in size.
Either way, the most important thing to remember that when it comes to a diamond, the carat weight is not the only factor which determines a diamonds value.
Refers to the presence of inclusions in a diamond. Inclusions are a natural identifying characteristics such as minerals or feathers that appear while diamonds are being formed and at times, may look like tiny crystals or clouds.Inclusions are usually viewed at 10x magnification. The position of inclusions can greatly affect the value of a diamond. Some inclusions can be hidden by a mounting, thus having little effect on the beauty of a diamond. An inclusion in the middle or top of a diamond could impact the dispersion of light, making the diamond less brilliant. Inclusions are ranked on a scale of perfection known as the clarity scale. The scale (as seen above) ranges from F (Flawless) to I (Included) and is based on the visibility of inclusions at 10X magnification.
Refers to the degree to which a diamond is colorless. The farther from colorless that a diamond's grade is, the less rare and less valuable it is on the market.
Diamonds are graded on a color scale established by the Gemological Institute of America (GIA), which ranges from D (Colorless) to Z.
Icy winter whites (D-I) look stunning in white gold or platinum. Warmer colored diamonds (J-Z) are more desirable when set in yellow gold. Color differences can be very subtle and grading is done under controlled lighting and compared against a master set of diamonds for accuracy.
Refers to the angles and proportions of a diamond. The cut of a diamond refers to the exact proportions, quality of polish and the arrangement of a diamond's facets. While nature determines a diamond's clarity, carat weight and color, the hand of a master craftsman is necessary to release the diamonds fire and sparkle. A diamond has facets that allow light to enter it, become refracted, and exit in a rainbow of colors. When a diamond is cut to ideal proportions, it is carefully polished and has exact symmetry, light will then reflect from one facet to another and disperse through the top of the stone, resulting in a dazzling display of brilliance and fire. Diamonds that are cut too deep or too shallow lose or leak light through the side or bottom, resulting in less brilliance, fire, scintillation and value. The cut can affect the value of a diamond by up to 60%!
Diamonds are also cut in different shapes and sizes where is all boils down to ones personal taste.
The stone is named after Prince Alexander of Russia (which is why the "A" in Alexandrite is capitalized), who become Czar Alexander II in 1855). They say the stone was discovered in 1839 on the day of the prince's birthday in an emerald mine in the Ural Mountains of Russia. However, because it is a relatively recent discovery, there has been little time for myth and superstition to build around this unusual stone. In Russia, the stone was also popular because it reflected the Russian national colors, green and red, and was believed to bring good luck.
The Alexandrite possesses an enchanting chameleon-like personality. In daylight, it appears as a beautiful green, sometimes with a bluish cast or with a brownish tint. However, under artificial lighting, the stone turns reddish-violet or violet. To this day, Alexandrite is an uncommon stone, and therefore very expensive.
The main source of Alexandrite today are mines in Sri Lanka as well as Brazil, Malagasy, Zimbabwe, Tanzania and Burma.
The Ancient Greeks believed that whomever wore this gemstone would be protected from the intoxicating effects of wine and the name is derived from the Greek word "amethustos" meaning, "not drunk". Amethyst, the birthstone for February, is a variety of quartz and occurs in transparent light to dark purple. It has long been treasured by kings, queens and religious figures, dating back to the Minoan period (c. 2500 B.C.), because of its rich, royal color. Amethyst was a favorite of the Art Nouveau craftsmen of the 1920's and is still a favorite of some of the most creative jewelry designers of today. The most notable reason for their popularity in jewelry design has been the wide availability and reasonable price.
The two main sources of amethyst are Brazil and Zambia, although other deposits have been found in Russia, Sri-Lanka, Mexico, and Arizona.
Latin for seawater, this beautiful gemstone inspires visions of the transparent azure blue waters of the Caribbean. Aquamarine is identifiable by its flawless crystallization and greenish-blue color, just like the Caribbean water that is so clear that you can see through the surface to the sand below. As the birthstone for March, aquamarine differs greatly from its most famous relative, emerald. Both are from the gemstone group known as beryl. However, while emeralds are almost always imperfect (having visible inclusions) aquamarines are almost always flawless (no visible inclusions under 10x power magnification).
Brazil is the most prolific supplier of aquamarine today, with the natural color from this area leaning towards bluish-green. Other sources of aquamarine include Tanzania, Kenya, Nigeria, Afghanistan, Russia, and the island of Sri Lanka.
Citrine is the lovely yellowish gem belonging to the quartz species of gemstones. Its name is derived from its lemon-yellow color and the French word "citron", meaning lemon. Most commercial citrines are heat-treated amethysts or smoky quartzes. Citrine is available in colors ranging from pastel yellows to wonderful orange hues, with the finest quality citrine being medium to dark in tone, vivid in intensity, and yellowish-orange in color. The warm hues are reminiscent of the sun, health and vitality, and represent an incredible value for those who appreciate its colors. Fun Fact: because of its beauty and lower price, citrine is commonly used a replacement for topaz as the birthstone for November.
Citrine is rather common in nature and found principally in Brazil, Bolivia and Spain.
The name emerald is derived from the Greek word Smaragdos meaning "green stone" and, in ancient times, it referred to just about any green colored gemstone. The birthstone for May, emerald is the most prized and precious variety of the gemstone group known as beryl, which also consists of aquamarine and other variations of beryl. The green color of emerald is incomparable in the world of gemstones and for this reason, the color is commonly referred to as "emerald green". Under magnification the internal characteristics in an emerald, which include liquid bubbles, gas bubbles, internal stress fractures, and foreign crystals form a virtual garden within the gemstone. Most natural Emeralds contain a variety of these internal inclusions, commonly referred to as "jarden", which is French for garden. Perfection in emerald, as in most all things, is the most rare of nature's treasures. Emerald is the birthstone for May and symbolizes rebirth and youth.
Most of the world's Emeralds are mined in Columbia, Brazil and Zambia.
Garnet is a group of gemstones that occurs in a virtual rainbow of colors. The name garnet is derived from the Latin word for grain, because of the round shape of the crystals, as well as the Greek word "granatum" for the pomegranate seed. The most common garnets are the reddish varieties, which bear the names Almandite, Pyrope, and Rhodolite. These gemstones occur in a range of colors from medium to dark reddish orange (Almandite and Pyrope) to purplish red to reddish purple (Rhodolite). Garnet is the traditional birthstone for the month of January, however, red need not be your color of choice if you were born in the first month of the year.
Other more interesting gems from the garnet family, being used in jewelry today, consist of pinkish orange tones (Malaia) to those that exhibit a variety of colors that have the ability to change tones, depending on the light source, and are known as color change garnets. Lesser known garnets occur in a yellowish orange (Spessartite) to the more rare varieties that occur in green tones (Tsavorite and Demantoid).
Gem of the Vikings. When legendary Viking explorers ventured far out into the Atlantic Ocean, far away from any coastline, they had a secret gem weapon: iolite. The Viking mariners used thin pieces of iolite as the world's first polarizing filter. Looking through an iolite lens, they could determine the exact position of the sun, and navigate safely to the new world and back. The property that made iolite so valuable to the Vikings is extreme pleochroism. Iolite has different colors in different directions in the crystal. A cube cut from iolite will look a violetish blue almost like sapphire from one side, clear as water from the other, and a honey yellow from the top. This property led some people to call iolite "water sapphire" in the past, a name that is now obsolete. Pleochroism may have been helpful in navigation but it makes things difficult for a gem cutter. If iolite is not cut from exactly the right direction, no matter the shape of the rough, its color will not show to its best advantage. The name iolite comes from the Greek ios, which means violet. Iolite is usually a purplish blue when cut properly, with a softness to the color that can be quite attractive. Iolite is readily available and surprisingly affordable. The better and richer the blue, the better the quality of the gem. With its attractive color and reasonable price, it may become a jewelry staple in the future.
Iolite is mined in India, Sri Lanka, Mozambique, Zimbabwe, and Brazil - Vikings probably mined iolite from deposits in Norway and Greenland.
The name opal is derived from an Indian word for "stone" and they are divided into three basic groups with physical properties that vary considerably:
- Precious opal - The special characteristic of these gems is their opalescence, more appropriately referred to as "play-of-color". The more predominant types within this group are white opals that are translucent to semitransparent with play-of-color against a white body color, black opals that are translucent to opaque with play-of-color against a black or other dark body color, jelly opals that are colorless, transparent to semitransparent with little or no play-of-color, and boulder opals which are opaque and made up of a thin layer of opal occurring in ironstone matrix; the opal is cut and polished for the top and the matrix stone is left as a backing that adds strength and a dark background. Opal always contains water in variable amounts, but it can be as much as 30%. If not cared for properly, opals can lose water over time causing crazing, or cracking. White opals will be the most common found in jewelry and the value of an opal gemstone will be more determined by its play-of-color than by size.
- Fire opal - These opals are some of the most interesting since they do not look like what the average consumer would identify as an opal. They are transparent to semitransparent with or without play-of-color on a yellow, red or orange body color. The most important deposits of fire opal are in Mexico and, for that reason, these beautiful gemstones are often called "Mexican Opals".
- Common opal - Very common, as the name would imply, and mostly opaque without play-of-color.
Opals, an optional birthstone for the month of October, are relatively soft gemstones and do not react well to heat or sudden changes in temperature. Opals are prized by many for their phenomenal play of color, and while they do make beautiful pieces of jewelry to be worn and appreciated, extreme care must be taken to protect these gems from damage. Because of their moisture content they require special care even when they are not being worn. When purchasing opal jewelry it is important to discuss their proper care with a gemologist, to insure that their beauty will be maintained and passed on from generation to generation.
The pearl is unique in the world of gemstones, as it is the only gemstone that is formed within a living creature. Known as the birthstone for the month of June, pearls are truly a treasured gift of the sea and revered for their colors, shapes, sizes and luster. As the supply of naturally occurring pearls became exhausted man learned how to cultivated them by implanting an irritant into oysters, which produced pearls having the same outer appearance as their natural counterpart. Cultured pearls are grown and harvested in many parts of the world, including the fresh waters of the Tennessee River, and are available in many beautiful colors, from the palest creme and white to rose, lilac, green, gold, gray and the dramatic Tahitian black. The majority, however, come from Japan, China and the South Pacific. Today, the pearls from the Japanese Akoyah oysters are becoming the most prized, as unfavorable biological and environmental conditions have reduced the availability of larger and finer quality pearls from the salt waters of Japan. Human innovation, however, has compensated for natures hardships as man has perfected the cultivation of the larger freshwater oysters in the lakes of China, producing an abundant crop of beautiful cultured pearls ranging from lustrous white to naturally occurring soft pastel colors. To find beautiful pearls in much larger sizes, exceeding nine and ten millimeters in diameter, one must look to warm waters of the South Pacific where magnificent whites from Australia and dramatic natural blacks from Tahiti are harvested to produce one-of-a-kind necklaces or combined with diamonds for truly magnificent pieces of jewelry. In the cultivation process of all pearls man can only begin the process by implanting an irritant within the muscle of the oyster. After that it is up to the mollusk to produce a fine gem, a very poor gem, or something in-between. Similar to the way any gemstone is judged, the value of any pearl will depend on rarity, beauty, size, color, luster and degree of perfection. In the case of a strand of pearls, the quality of how well the pearls are matched is also an important consideration. In the world of pearls there is something for everyone.
Peridot has been adored since early times, when the ancient Egyptians prized it more than 3500 years ago. Some jewelry historians are convinced that some, if not all, of the emeralds Cleopatra was famous for wearing were actually peridots mined from what is now known as St. John's Island in the Red Sea, about 34 miles off the coast of Egypt. Peridot is a member of the olivine family of gemstones and is the birthstone for August. This beautiful lime-green gemstone depends largely on body mass for its concentration of color and, hence, its beauty. Unfortunately, larger stones have become so rare that the green hue for which this gem is most praised is seldom seen today.
Much of today's peridot comes from Arizona, however, stones rarely exceed 3 carats in size. Peridot is also found Australia, Brazil, China, Myanmar (Burma) and Pakistan.
Ruby, "the King of Gems" and birthstone for July, gets its name because of its red color and is derived from the Latin word Rubeus, meaning red. It was discovered around 1800 that Ruby, as well as sapphire, belonged to the same mineral group, or species, called corundum. Prior to that date, both red spinel and garnet were thought to be, or were referred to, as Ruby. In fact, many of the most prominent red gemstones in England's Royal Jewels are magnificent red spinels which, for years, were thought have been rubies. The red color in Ruby is derived from chromium and historically, the most desirable ruby color is denoted by the term "pigeon’s blood". The red color of Ruby will vary from deposit to deposit and it is, therefore, not possible to determine the source area of a Ruby based on its color.
Ruby is mined throughout Southeast Asia and while the majority is found in Thailand and Myanmar (Burma), many exquisite gems also are found in Sri Lanka and Africa. The designation Burmese-ruby or Siam-ruby are trade names and refer more to color quality than to actual origin.
Birthstone for the month of September, the name Sapphire comes from the Greek word "Sappheiros", meaning blue. However, sapphires are formed in nature in a literal rainbow of colors, ranging from very light to very dark blue, bluish green, yellow, brown, pink, violet, slightly reddish orange, and a fabulous pinkish-orange that is referred to as "padparadscha". The name padparadscha is derived from the Sinhalese for "lotus flower". The mineral name for sapphire is Corundum and its pure red form it would be known as ruby. The finest sapphire color in the blue hues is a rich, velvety, cornflower blue known as "Kashmir", which references the area of India where these precious gemstones were once mined.
Most current production comes from Sri Lanka, Burma, Thailand, Australia, Africa and Montana.
Blue Star Sapphire
Sapphire sometimes displays a three-ray, six-point star. These star sapphires are cut in a smooth domed cabochon cut to display the effect. The star is best visible when illuminated with a single light source: it moves across the stone as the light moves. This effect, called asterism, is caused by light reflecting off tiny rutile needles, called "silk," which are oriented along the crystal faces. The values of star sapphires are influenced by at least these two things: 1) the intensity and attractiveness of the body color, and 2) the strength and sharpness of the star. Of course all six legs should be straight and equally prominent. Star sapphires rarely have the combination of a fine translucent or transparent color and a sharp prominent star, but when offered, these gems are highly valued and the most expensive.
At its breathtaking best, tanzanite will look amazingly like Kashmir sapphire, exhibiting the rich, royal velvety blue hue that those gemstones are prized for, at a fraction of the price. This exquisite gemstone is renowned for the wonderful combination of purple and blue hues, observed in different intensities within the same gemstone. Tanzanite is a trichroic gemstone, meaning that it gives off three different colors when viewed in different directions, or along the optic axis. The dominant colors being blue and violet will cause tanzanite to appear violet when exposed to incandescent light and blue when exposed to fluorescent light. The third less dominant color is reddish brown or bronze, which is rarely visible to the naked eye. Tanzanite is a form of zoisite, which was named tanzanite due to its original discovery in Tanzania in 1967 and, to date, it is not found in any other place in the world. The introduction and popularity of the gemstone can be attributed to Tiffany and Company, who exclusively marketed the gemstone in the late 1960's and early 1970's. The American Gem Society has designated tanzanite as an option for the traditional December birthstones blue zircon and turquoise. Tanzanite is one of the most popular blue gemstones available today and while it has the beauty, rarity and durability to rival most colored gemstones, your tanzanite needs slightly more care and attention than due other harder gemstones, such as sapphire.
The name topaz was probably derived from the ancient island of Topazios in the Red Sea. In ancient times all yellow, brown, and sometimes green gemstones were called "topaz". Even through modern times, the brownish gemstone commonly referred to as Smokey Topaz is not topaz at all. Thanks to the adoption of Federal Trade laws, which have been successful in eliminating most of the misrepresentation of colored gemstones, the proper gem variety name, Smokey Quartz, is now used to describe these gems. The quartz variety citrine and yellow heat-treated amethyst have at times been falsely called "golden topaz" in the jewelry trade, which lead to real topaz being referred to as "precious topaz". Commonly, one of the orangey or golden colors of topaz is worn as the traditional birthstone for November. Topaz, however, can be found in a rich rainbow of colors with the most valuable being "Imperial" topaz and pink topaz. Imperial topaz derived its name after the Russian Czars of the 1800's, and has a magnificent orange body color, with pinkish-red undertones. In addition to these two, topaz can be found naturally in yellow, reddish-brown, light blue, pinky-red, pale green and colorless.
Due the abundance of blue topaz, along with its captivating beauty and low price, it has become an ideal replacement option for aquamarine as the birthstone for March.
Tourmaline, like garnet and sapphire, occurs in almost every color of the rainbow from soft pastel tones to bold and brilliant colors that excite the senses. The people of ancient Ceylon referred to these beautiful gems as "turmali", the Sinhalese word for many colors. Varying vibrant hues within the tourmaline group are such that they command a name that separates them from the more common hues. The vivid reds and hot pinks are known as Rubellite, vibrant greens that crystallized containing the chemical chromium and are called Chrome Tourmaline, and the violetish to greenish blues are referred to as Indicolite. The pink variety is often used as the birthstone for October. Not only does tourmaline occur in such a spectacular range of color, some of these colors occur in a single gemstone and are called "bi-color" or "parti-colored" tourmalines. In fact, one color combination known as "watermelon" tourmaline, occurs with a pink center and green perimeter.
Tourmaline is mined in many areas of the world including Brazil, Afghanistan, East Africa and the United States.
December's primary birthstone. Turquoise is considered by some to be a symbol of good fortune and success, believed to bring prosperity to its wearer. It's name is believed to originate from the French phrase "pierre turquoise" meaning "Turkish stone" because turquoise was brought to Europe by Venetian merchants who first acquired it in Turkish bazaars. It is also considered by some as a love charm. When received as a gift, the turquoise symbolizes a pledge of affection. Shakespeare used this lore in "The Merchant of Venice". In it, Leah gave a turquoise ring to Shylock when he was a bachelor, hoping it would win his affections so he would ask her to marry him. In Russia, the turquoise is popularly used in wedding rings. In the language of chemists and geologists, turquoise is known as "copper aluminum phosphate". Turquoise is often found in weathered igneous rock that contains copper minerals, where it crystallizes in veins and nodules. The gemstone usually develops in rock near water tables, located in semiarid and arid environments. The chemicals in turquoise come from adjacent rock, leached out by rain and groundwater. Turquoise is a relatively soft gemstone, and can be easily scratched and broken. This porous opaque stone is easily discolored by oil and pigments, and changes color when it loses some of its water content. A sky blue shade in turquoise is due to the presence of copper, while iron gives it a greener tone. Ochre and brown-black veins in the stone occur during the formation of turquoise, caused by inclusions from nearby rock fragments or from oxide staining. The most valued variety of turquoise is an intense sky blue color, like the color of a robin's egg. Hard, relatively non-porous compact stones have the best appearance because the stone can be finely polished.
The alternate birthstone for December is the zircon. Its name is probably derived from the Arabic words "zar" and "gun", meaning "gold" and "color". The gemstone is found in a wide range of colors, and possesses great brilliance, fire and clarity. Zircon, in its unchanged natural form appears colorless to pale yellow, or green. These colors are caused by minute quantities of thorium and uranium that replaces zircon in the crystal structure. But over the vast spans of geologic time, other forces work within the zirconium silicate crystals. The uranium and thorium inclusions emit radiation that alters the original crystal structure. A glass-like material is formed, with colors of red to brown, orange and yellow. Gem quality zircon stones are usually rare. These gemstones are formed mainly in pegmatites (coarse-grained igneous rock) and in fissures. But due to weathering of the gem-bearing rocks, most zircons are found in alluvial and beach deposits. A new blue color for zircon, called "starlight blue," was created by heating golden brown or yellow zircon in the 1920's. The most prized zircon is the red gemstone, which is rare. The pure intense blue and sky blue varieties are also highly valued, while the colorless, orange, brown and yellow stones are less expensive. Many zircons on the market are heat treated, and sold as blue, golden brown or colorless stones. Colorless zircons are the best imitators of diamonds, in appearance only, with a brilliant fire that is almost as dazzling as the real thing. However, the resemblance is superficial. Zircon is a brittle stone, easily broken with a well-placed knock, due to internal stresses in the crystal caused by radiation damage and heat treatment. But despite its frail disposition, the stone is still highly valued because of its stunning beauty.
Contemporary Metals Used for Jewelry