Colored Stone education
Ruby, “the King of Gems” and birthstone for July, gets it’s 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 “pigeons 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. Internal characteristics, or inclusions, are very common and while these inclusions are not necessarily indicative of lower quality, they may show the difference between natural and synthetic. Certain types of inclusions may also indicate the source area, or origin, of the gemstone.
The word “Emerald” is derived from Old French: Esmeraude, meaning “emerald” or “green” and a fine emerald must possess not only a pure verdant green hue, but also a high degree of transparency to be considered a top gem. Emerald is regarded as the traditional birthstone for May. . Emerald is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes vanadium. Emerald tends to have numerous inclusions and surface breaking fissures. Thus, if an emerald has no visible inclusions to the eye (assuming normal visual acuity) it is considered flawless. Stones that lack surface breaking fissures are extremely rare. Since most emeralds are highly included, their toughness (resistance to breakage) is classified as generally poor. Emeralds in antiquity were mined by the Egyptians and in India and Austria. Today, Emeralds primarily come from three main emerald mining areas in Colombia: Muzo, Coscuez, and Chivor. They are also found in other countries, such as Australia, India, Madagascar, Mozambique, Tanzania and Zimbabwe to name a few.
The word Sapphire comes from the Greek word sappheiros, meaning “blue stone”. A gemstone variety of the mineral corundum, sapphires can be found naturally, by searching through certain sediments or rock formations. Sapphire is regarded as the traditional birthstone of September and the mining locations include Burma, Madagascar, Sri Lanka, Australia, Thailand, India, Pakistan, Afghanistan, Tanzania, Kenya, and China. The cost of natural sapphires varies depending on their color, clarity, size, cut, and overall quality – as well as their geographic origin. The color of fine blue sapphires can be described as a vivid medium dark violet to purplish blue. Blue sapphires with any amount of green as a secondary hue are not considered to be fine quality. Sapphires are commonly worn in jewelry and the 423-carat (85 g) Logan sapphire in the National Museum of Natural History, in Washington, D.C., is one of the largest faceted gem-quality blue sapphires in existence.
Alexandrite is a gem variety of the mineral chrysoberyl discovered in 1830 in Czarist Russia. Alexandrite is a color changing gem. Outside in daylight it is a cool bluish mossy green. Inside in lamplight , it is a red gem , with a warm raspberry tone. Since the old Russian imperial colors are red and green, it was named after Czar Alexander II on the occasion of his coming of age. Fine alexandrite is most often found in period jewelry since newly mined gems are extremely rare. The original source in Russia’s Ural Mountains has long since closed after producing for only a few decades, but some Alexandrite is still found in Sri Lanka, Zimbabwe and Brazil. Although alexandrite remains extremely rare and expensive, the production of a limited amount of new material means a new generation of jewelers and collectors have been exposed to this beautiful gem creating an upsurge in popularity and demand.
Tanzanite is a member of the Zoisite family of minerals. The name for the gemstone known as Tanzanite is taken from it’s place of origin, the country of Tanzania. Tanzanite is an exotic, vivid blue, kissed by purple hues. Legend has it that tanzanite was first discovered Masai herders driving cattle noticed the beautiful blue color and picked the crystals up. Tanzanite has the beauty, rarity and durability to rival any gemstone and has become quite popular. In fact Tanzanite is so popular it has the honor of being the first gem added to the birthstone list (December) since 1912 by the American Gem Trade Association.
Peridot is a member of the Olivine family and is treasured in Hawaii as the goddess Pele’s tears. The island of Oahu even has beaches made out of tiny grains of peridot. The fresh lime green of peridot is its distinctive signature. Peridot is the birthstone of August and today is primarily mined in Arizona. Faceted peridot in sizes above five carats are rare but they are found in Burma and in China. The most valued color is a dark olive-green.
Opal is an amorphous form of silica related to quartz. Revered as a symbol of hope fidelity and purity, opal was dubbed the Queen of Gems by the ancient Romans because it encompassed the colors of all other gems. Opal, the birthstone for October, is prized for its unique play of color, the ability to diffract light into flashes of rainbow color. The most common is white opal and the most valued is black opal. Mined primarily in Australia, Mexico, and the United States opals are cut into rounded or free form cabochons that enhance their color play.
Iolite is a blue silicate mineral that occurs as crystals. Seafaring Vikings used iolite to filter the haze and glare from their eyes. The name is from the Greek “Ios” meaning violet. Iolite has a pleasing color of blue and the most desirable color is rich violet-blue. Mined in Sri Lanka, Africa and Brazil and can be obtained in sizes up to 4 to 5 carats reasonably easily although much larger gems have been found. This pleasing blue gemstone is commonly cut into traditional shapes and is gaining widespread popularity for its beauty and attractive affordability.
Garnets are nesosilicates and traces its roots to the Nile Delta in 3100 B.C., where Egyptian artisans would craft the gemstones into beads or inlay them into hand-wrought jewelry. Garnet, the official birthstone for January, received its name from the ancient Greeks because the color reminded them of the “granatum” , or pomegranate seed. Mined in Madagascar, it is also found in parts of the United States, Russia and Turkey. The versatile garnet comes in a rainbow of colors, from the deep red Bohemian Garnet to the vibrant greens of the Russian Demantoid and the African Tsavorite.