umptekite

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English

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Noun

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umptekite (countable and uncountable, plural umptekites)

  1. (mineralogy) A syenitic rock consisting of microperthite, arfvedsonite, aegirine and, possibly, nepheline.
    • 1905, John Henry Sears, Essex Institute, The Physical Geography, Geology, Mineralogy and Paleontology of Essex County, Massachusetts, page 213:
    The rock-mass in which this umptekite form of hornblende occurs may therefore be called umptekite gabbro.
    • 1920, Alfred Reginald Schultz, Oil Possibilities in and Around Baxter Basin, page 85:
      The Beverly syenite includes the alkaline syenites of Beverly, Manchester, Salem, and Marblehead, comprising pulaskites and umptekites.
    • 1956, The Quarterly Journal of the Geological Society of London, page 210:
      There Strauss & Truter record a gradual transition from the white umptekite (fenite) to a pulaskitic rock with nepheline.

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