Beautiful natural green Tourmaline (2ct, Type3 S12, USA) hand set in 925 sterling silver ring.Once proposed to be the national gemstone of the United States, tourmaline is found all over the world and in a variety of colors. Tourmaline is the most colorful of all gemstones because, according to an ancient Egyptian legend, it passed through a rainbow on its journey to Earth and brought all of the colors of the rainbow with it. Tourmaline is actually a group of gem species with the same crystal structure and slightly different chemical properties, which account for all of its different colors. All tourmalines are aluminum boron silicates that contain a variety of other elements that give each species their different appearances. Major tourmaline species include liddicoatite, dravite, uvite, schorl, and the most important one, elbaite, which encompasses most gem tourmalines and the widest range of gem-quality colors.Tourmalines occur naturally in every color of the rainbow, sometimes even two colors at once. In fact, tourmaline crystals are more likely to have two (or more) colors than just one--or at least two or more tones of one color. Even minor changes in a tourmaline's chemical composition can serendipitously result in entirely different colors within the single crystal. When tourmaline grows so that the center is red with white or colorless material around it, and green around both of those, it's known--not surprisingly--as watermelon tourmaline. It's usually cut in thin slices or cross-sections to best show off its interesting color growth. Tourmalines from Malawi, known as canary tourmaline, are a vivid yellow color. In addition to usually being bi- or tricolored, showing two or more colors from one view, tourmaline is also strongly pleochroic, meaning a stone that appears to be only one color face-up can appear to be two or more colors, or tones of the same color, depending upon which direction it is viewed. Look through the gem's table with a dichroscope and you'll see both of tourmaline's pleochroic colors. Light To Strong Pink , Orangy Red , Red , Purplish Red , Purple , Inky Blue , Blue , Bluish Violet , Violet , Greenish Blue , Light To Dark Green-Blue To Yellowish Green , Dark Green , Yellow , Orange , Brown , Dark Brown , Black , Rarely ColorlessThis item can be precious metal wrapped, charges apply.Please ask questions.