The story
After the town of Tyndall, Manitoba, where the stone is quarried, in turn named after Irish physicist John Tyndall (1820–93). Tyndall, Tindall (“inhabitant of the Tyne river valley”) < Tyne.
Etymology from Wiktionary, CC BY-SA 4.0.
Tyndall stone
Today it means: A dolomitic limestone quarried in the vicinity of Tyndall, Manitoba, Canada, famous for its pervasive mottling and numerous fossils. Full definition →