umptekite

== English == === Noun === umptekite (countable and uncountable, plural umptekites) (mineralogy) A syenitic rock consisting of microperthite, arfvedsonite, aegirine and, possibly, nepheline. The rock-mass in which this umptekite form of hornblende occurs may therefore be called umptekite gabbro. === References === Mindat.org‎[1], Hudson Institute of Mineralogy, 2000–2026.