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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.
In late classical times and as late as the Middle Ages, lapis lazuli was often called sapphire (sapphirus in Latin, sappir in Hebrew), [28] though it had little to do with the stone today known as the blue corundum variety sapphire. In his book on stones, the Greek scientist Theophrastus described "the sapphirus, which is speckled with gold," a ...
The Numismatic Museum of Athens (Greek: Νομισματικό Μουσείο Αθηνών) is one of the most important museums in Greece and it houses a collection of over 500,000 coins, medals, gems, weights, stamps and related artefacts from 1400BC to modern times. [1]
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.
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 three most important standards of the ancient Greek monetary system were the Attic standard, based on the Athenian drachma of 4.3 grams (2.8 pennyweights) of silver, the Corinthian standard based on the stater of 8.6 g (5.5 dwt) of silver, that was subdivided into three silver drachmas of 2.9 g (1.9 dwt), and the Aeginetan stater or didrachm of 12.2 g (7.8 dwt), based on a drachma of 6.1 g ...
Now, with the Christmas Day opening of the second film based on Walker's 1982 book, purple takes a seat at the box office after the historic popularity of “Barbie” and all things pink.
The tradition goes back to ancient Mesopotamia with books like Abnu šikinšu. Theophrastus (died c. 287 BC) treated rocks and other minerals as well as gems, and remained a significant indirect source for the scientific tradition; he was all but unknown in Europe in the Middle Ages, and not translated into Latin until the 15th century. [8]