At 23.10cts, the Carmen Lucia Ruby is the largest faceted ruby in the National Gem Collection and one of the finest large, faceted Burmese rubies known. This natural ruby possesses a combination of outstanding characteristics. Aside from its large size, this extraordinary gemstone displays a richly saturated homogenous red color, combined with an exceptional degree of transparency. The stone was mined from the fabled Mogok region of Burma in the 1930s. While sapphire, emerald, and diamond gems weighing hundreds of carats exist, high-quality Burmese rubies larger than 20 carats are exceedingly rare. This magnificent ruby was a gift to the National Gem Collection and the people of the United States from Dr. Peter Buck, in memory of his loving wife, Carmen Lucia Buck, who was born in Brazil and became a U.S. citizen. Her love for the United States, devotion to children, and appreciation for fine jewelry inspired the gift of this ruby for the children and families of the American People to enjoy.
Sapphire is a variety of the mineral corundum. Pure corundum is colorless, but small amounts of impurity atoms imparted in the crystals as they grow can produce a range of vivid colors. A few atoms of chromium tint corundum the deep red color of ruby, the most prized corundum gem. Iron and titanium, on the other hand, are responsible for the deep blue color of sapphire. Other impurity atoms can color corundum crystals a range of hues, from pink, yellow, and orange to purple, green, and even black. Corundum gems other than red or blue are called fancy sapphires. The fancy colored sapphires pictured here range in size from 10.3 to 92.6 carats. The green and large yellow sapphires are from Burma; the others are from Sri Lanka.
The Hall sapphire and diamond necklace, designed by Harry Winston, Inc., features 36 matched sapphires from Sri Lanka, totaling 195 carats. Their soft sky blue color is accented by 435 pear-shaped and round brilliant-cut diamonds, totaling 83.75 carats. Sri Lanka has been an important souce of sapphires, rubies, and other gemstones for more than 2,000 years. The stones that have eroded from Sri Lanka's central mountains are still picked by hand from alluvial gravel deposits that cover most of the southern half of the island. Sapphires from Sri Lanka are typically light to medium blue in color and can be very large in size.
Sapphire is a blue, yellow, orange, pink, purple, green or clear variety of the mineral corundum. Pure corundum is colorless, but tiny amounts of impurity trapped in the crystals as they grow result in a range of vivid colors. Iron and titanium are responsible for the deep blue color of sapphires. This 175.1-carat sapphire crystal reveals the typical natural shape of corundum crystals. To obtain the deepest color, gems are oriented so that the top of the cut stone is perpendicular to the length of the crystal. If this corundum crystal was cut, the faceted gems would probably be pink or purple in color. Today, ninety percent of corundum is heat-treated to enhance its color.
Beautiful blue sapphires have been mined from near Yogo Gulch, Montana, since about 1895 and have found their way into the prestigious gem collections of the world. The crystals rarely yield gems larger than a few carats. This assortment of Montana sapphires ranges in weight from 1.9-10.2 carats. Although commonly thought of as blue gems, sapphires exist in a variety of colors, depending on the chemical impurities present in their atomic structures. Sapphires other than blue are called "fancy-colored."
The 98.57-carat Bismarck Sapphire is mounted in a diamond and platinum necklace, designed by Cartier, Inc. The sapphire exhibits the highly-valued deep blue color of fine sapphires from Burma. The necklace is named after its donor, Countess Mona von Bismarck, an American socialite who married German Count Eduard von Bismark. She donated the necklace to the Smithsonian in 1967.
Even though sapphires are traditionally thought of as blue in color, they occur in a wide variety of colors: yellow, orange, green, purple, pink, and colorless. If a sapphire is not blue then it is termed "fancy color." The majority of fancy-colored sapphires seen in the jewelry trade are from Sri Lanka. Yellow and pink are the most common fancy sapphires used in jewelry, but the rarest and most valuable is the pinkish-orange variety known as padparadscha, named for the lotus flower whose color it resembles. This padparadscha sapphire from Madagascar has exceptional color and is the largest and finest in the National Gem Collection. It was generously gifted in 2002 by Pasha and Laney Thornton.
This spectacular butterfly brooch highlights the amazing color range of natural sapphires from Montana. The 18k yellow gold butterfly is set with 331 round brilliant-cut sapphires and 2 cabochon cut sapphires, totaling 27.97 carats. The exquisitely crafted piece is extremely versatile and can be worn as a brooch, pendant, or clasp. Most of these fancy-colored sapphires are from the famed Rock Creek deposit, located in the Sapphire Mountains near historic Philipsburg, Montana. More popularly known as Gem Mountain, gold miners discovered sapphires here in the late 1890's. Over a period of 110 years, several hundred million carats of gem-quality sapphire were produced from this site that noted gemologists and journalists describe as the "Rainbow Over Montana." The Montana Sapphire Butterfly, a collaboration by jewelry designer Paula Crevoshay and gem dealer Robert Kane, was generously given by them to the Smithsonian Institution's National Gem Collection in 2007.
Some of the most interesting members of the gem kingdom are those reflecting bright bands of light that form stars. This optical phenomenon, called chatoyancy, is caused by light reflecting off of parallel bundles of tiny hollow tubes or fibrous crystals of another mineral inside the gemstone. When a properly oriented stone is cut en cabochon, round or oval shape with a domed top and flat bottom, the star is visible. This exceptional 16.21 carat Sri Lankan star ruby, the "Star of Katandru," has a well-centered star with straight arms of sharp intensity, and a uniform and beautiful body color. The Star of Katandru, named in honor of the donor's children, was generously gifted by Jeffrey Bilgore in 2004.