Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green. Because trace amounts of chromium and sometimes vanadium.
Beryl has a hardness of 7.5 to 8 on the Mohs scale. Most emeralds are ususualy full of onclusions, so their toughness (resistance to breakage) is generally poor. It is a cyclosilicate.
The word “emerald” is derived (via Old French: esmeraude and Middle English: emeraude), from Vulgar Latin: esmaralda/esmaraldus, a variant of Latin smaragdus, which originated in Ancient Greek: σμάραγδος (smaragdos; “green gem”).
Emeralds, like all colored gemstones, are graded using four basic parameters the four Cs of Connoisseurship: Color, also Clarity, Cut and Carat weight. Before the 20th century, jewelers used the term water, as in “a gem of the finest water”, to express the combination of two qualities: color and clarity. Normally, in the grading of colored gemstones, color is by far the most important criterion. However, in the grading of emeralds, clarity is the second one. A fine stone must possess not only a pure verdant green hue as described below, but also a high degree of transparency to be a top gem.
During the twentieth century, the Chivor mine passes through the hands of several companies. Including a German owner, many US investors and Canadian society “Chivor Emerald”. We discovered the largest emerald of history in 1920. The name of this emerald is “Patricia” in honor of the daughter of the operator of the mine. The sale price of this632 carats emerald (126.4 grams) was the modest sum of $ 60,000
Natural Emerald 7.19ct with Pyrite inclusions, from Chivor, Colombia
Chivor is a town and municipality in the Eastern Boyacá Province, part of the Colombian department of Boyacá. The mean temperature of the village in the Tenza Valley is 18 °C (64 °F). Chivor is located at 215 kilometres (134 mi) from the department capital Tunja. Chivor is world-famous for its emeralds
Emerald rough from Madagascar