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  2. Verneuil method - Wikipedia

    en.wikipedia.org/wiki/Verneuil_method

    In 1947, the Linde Air Products division of Union Carbide pioneered the use of the Verneuil process for creating such star sapphires, until production was discontinued in 1974 owing to overseas competition.

  3. Star sapphire - Wikipedia

    en.wikipedia.org/wiki/Star_sapphire

    Star sapphire, a type of sapphire gemstone that exhibits a star-like reflection of light (an asterism) The Armstrong Siddeley Star Sapphire, a British car manufactured from 1958 to 1960; Star Sapphire (DC Comics character), the name of several fictional supervillains in DC Comics publications; Star Sapphire, a fictional character from the ...

  4. Sapphire - Wikipedia

    en.wikipedia.org/wiki/Sapphire

    A star sapphire is a type of sapphire that exhibits a star-like phenomenon known as asterism; red stones are known as "star rubies". Star sapphires contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"-shaped pattern when viewed with a single overhead light source.

  5. Asterism (gemology) - Wikipedia

    en.wikipedia.org/wiki/Asterism_(gemology)

    The star-effect may be also caused by the inclusions of hematite. In black star sapphire hematite needles formed parallel to the faces of the second order prism produce asterism. Some star sapphires from Thailand contain both hematite and rutile needles forming a 12-ray star. [3] Star-stones were formerly regarded with much superstition. [1]

  6. Linde plc - Wikipedia

    en.wikipedia.org/wiki/Linde_plc

    Linde Gas gaseus nitrogen plant. Linde PLC is a global multinational chemical company. It was created as a result of a merger in 2018 of American company Praxair and Linde AG and is domiciled in Ireland and headquartered in the United Kingdom. Linde is the world's largest industrial gas company by market share and

  7. Black Star sapphire - Wikipedia

    en.wikipedia.org/wiki/Black_Star_sapphire

    Black star sapphire, also known as 'natural star sapphire' is a type of corundum (aluminum oxide). It is usually cut into a dome shape to show a star feature. If it is cut with a flat or almost flat face, then a golden colour is revealed. The chemical composition and features for black star were analyzed in the Journal of Gemmology. [citation ...

  8. Wikipedia : WikiProject Gemology and Jewelry/Gemstones

    en.wikipedia.org/wiki/Wikipedia:WikiProject...

    This page is a subtopic of Wikipedia:WikiProject Gemology and Jewelry, and is designed to enable the expansion and improvement of Gemology and Jewelry related articles. Gemology and Jewelry Wikipedians

  9. List of sapphires by size - Wikipedia

    en.wikipedia.org/wiki/List_of_sapphires_by_size

    Sapphire Origin Date Size Cut Color Location Ref Star of Adam: Sri Lanka 2015 1,404.49 carats (280.898 g) Star Blue Anonymous owner [3] Black Star of Queensland: Australia 1938 733 carats (146.6 g) Star Black Anonymous owner [4] Star of India: Sri Lanka 563.4 carats (112.68 g) Star Blue-gray American Museum of Natural History, New York [5]