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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.
The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros (σάπφειρος), which referred to lapis lazuli. [2] It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors.
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.
Ancient Greek mythic-cultural cosmology depicted a decline from a golden age to a silver age followed by an Iron Age. In some variants there is a Bronze Age, an interim between the Iron Age and Silver Age. In Japan, the traditional Sho Chiku Bai (松竹梅) ranking system has a hierarchy of pine 松 (matsu), bamboo 竹 (take), and plum 梅 (ume ...
Sapphire Sapphire. Sapphire - Greek ὑάκινθος hyakinthos; Vulg. hyacinthus ; the eleventh stone of the foundation of the heavenly city (Revelations 21:20). The genuine sapphire is a beautiful blue hyaline corundum and is composed of nearly pure alumina, its color resulting from the presence of iron oxide. Sapphire was obtained from India.
The level of mineral purity within the extracted ore was incredibly rare throughout the ancient Greek world and Athens had exclusive access to it. [6] Athens would then use their access to the Laurion mines to direct a majority of the silver to be made into coins that would be used to pay for the famous Athenian navy. [6]
There is evidence that iron was known from before 5000 BC. [15] The oldest known iron objects used by humans are some beads of meteoric iron, made in Egypt in about 4000 BC. The discovery of smelting around 3000 BC led to the start of the Iron Age around 1200 BC [16] and the prominent use of iron for tools and weapons. [17]
Corundum is a crystalline form of aluminium oxide (Al 2 O 3) typically containing traces of iron, titanium, vanadium, and chromium. [3] [4] It is a rock-forming mineral.It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. [7]