Darling # 10
Inel din argint cu piatra semipretioasa peridot
Peridot is a gem-quality variety of the mineral olivine. It belongs to the forsterite-fayalite mineral series. Some even refer to peridot as ‘olivine’, but when it comes to the gemstone, ‘peridot’ is the correct term. Peridot is an idiochromatic gem, meaning its color comes from the basic chemical composition of the mineral itself and not from minor traces of impurities. Thus, peridot is found only in green. In fact, peridot is one of the few gemstones available that can be found only in one color, although the shades of green may vary from light yellowish to dark brownish-green.
Chemically, peridot is an iron magnesium silicate and its intensity of color depends on the amount of iron it contains. There may also be traces of nickel and chromium present.
Most gemstones are formed in earth’s crust, but peridot is formed much deeper in the mantle region. Peridot crystals form in magma from the upper mantle and are brought to the surface by tectonic or volcanic activity where they are found in extrusive igneous rocks. Historically the volcanic island Zabargad (St. John) in the Red Sea was the location of the most important deposit. It was exploited for 3500 years before it was abandoned for many centuries; later, it was rediscovered around 1900 and has been heavily exploited ever since.
Peridot is one of the few gemstones that comes in a single color. The depth of green depends on its level of iron content. Peridot’s color can vary from yellow-green and olive to brownish green and looks best under natural daylight. Its vivid green color does not change under artificial light. The best colored peridot has an iron percentage of less than 15% and typically includes some trace elements of nickel and chromium, which contribute to its color.
Peridot Clarity and Luster
Peridot occurs with excellent transparency. Eye-clean specimens are abundant. Larger stones may appear slightly cloudy owing to the presence of inclusions and impurities. When cut and polished, peridot has an attractive, greasy and vitreous luster.ComandaLike