umptekite

English

Noun

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.

References

• Mindat.org‎^[1], Hudson Institute of Mineralogy, 2000–2024.