The story
From Impson + -ite, after a sample from the Impson Valley (later reclassified as grahamite); coined by George Homans Eldridge in 1901.
Etymology from Wiktionary, CC BY-SA 4.0.
impsonite
Today it means: A black carbonaceous substance, believed to be derived from a fluid bitumen which polymerized after filling a vein. Full definition →