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Sapphires are a precious gemstone, a variety of the mineral corundum, consisting of aluminum oxide (α-Al 2 O 3) with trace amounts of elements such as iron, titanium, chromium, copper, or magnesium. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors.
The sapphire bearing Yogo dike is a dark gray to green intrusive rock known as a lamprophyre. The lamprophyre is an unusual igneous rock that contains a low content of silica. The rock has a porphyritic texture with large crystals of orthopyroxene and phlogopite set in a fine grained matrix. The phlogopite crystals have been used to determine ...
Asterism on the surface of a blue star sapphire. A purple-pink star sapphire displaying asterism in a platinum ring.. An asterism (from Ancient Greek ἀστήρ (astḗr) 'star' and -ism) is a star-shaped concentration of light reflected or refracted from a gemstone.
Padparadscha sapphires are rare; the rarest of all is the totally natural variety, with no sign of artificial treatment. [12] The name is derived from the Sanskrit padma ranga (padma = lotus; ranga = color), a color akin to the lotus flower (Nelumbo nucifera). [13] Among the fancy (non-blue) sapphires, natural padparadscha fetch the highest prices.
The five cardinal gems. Clockwise from top: sapphire, ruby, emerald, amethyst, diamond. Cardinal gems are gemstones which have traditionally been considered precious above all others. The classification of the cardinal gems dates back to antiquity, and was largely determined by ceremonial or religious use as well as rarity. [1]
The “incredibly rare” lump was unearthed at a 1,700-year-old bathhouse in the United Kingdom. ‘Mysterious’ purple lump found at ancient Roman ruins was once ‘worth more than gold’ Skip ...
Nevertheless, diamonds, rubies, sapphires, and emeralds still have a reputation that exceeds those of other gemstones. [26] Rare or unusual gemstones, generally understood to include those gemstones which occur so infrequently in gem quality that they are scarcely known except to connoisseurs, include andalusite, axinite, cassiterite ...
The most popular form of sapphire is blue sapphire, which is known for its medium to deep blue colour and strong saturation. Fancy sapphires of various colours are also available. In the United States, blue sapphire tends to be the most popular and most affordable of the three major precious gemstones (emerald, ruby, and sapphire). Turquoise