Massive greenish-gray Triphylite was mined as an ore of lithium at Hagendorf Pegmatite, Waidhaus, Bavaria, Germany. Triphylite, often in altered form replaced by oxides, has come from the Assunção Mine, Ferreira de Aves, Sátão, Viseu District, Portugal.

In the U.S., the pegmatites of New England are the best producers of Triphylite, including those at New Hampshire, Connecticut, and Maine.The Chandlers Mill Quarry, Newport, Sullivan Co., New Hampshire, has produced large and visible crystals in the best examples of this mineral. Also in New Hampshire is the Palermo No. 1 Mine, Groton, Grafton Co., where Triphylite has been found in mostly massive forms, but also in occasional crystals. Massive Triphylite has also come from Keystone, Pennington Co., South Dakota.