Old Mine Park, Trumbull

Old Mine Park covers 72 acres of rocky woods in the Long Hill section of Trumbull, owned by the town and surrounded by houses, stores and highways. At its center is the mineral-rich hill once called Saganawamps. In 1825 the geologists Hitchcock and Silliman recorded topaz here, the first topaz locality identified in the United States. Later the hill gave up tungsten, and the park preserves the first tungsten mine worked east of the Mississippi. It is also the type locality of tungstite, a hydrated tungsten oxide, meaning the mineral was first described from rock found here.

In a 1921 paper in American Mineralogist, Earl V. Shannon of the U.S. National Museum described a visit. He walked in along the railroad from Long Hill station, a little less than a mile, and found the mine openings and the ruins of the burned mill in plain sight from the tracks. The tungsten ore, he wrote, had come from the lower contact of a thick bed of coarse white marble set in deep green amphibolite schist, and the famous specimens were large pseudomorphs of wolframite after scheelite: one tungsten mineral replacing another crystal while keeping its shape. By his day those were no longer to be had. He still found plenty: nodules of deep red garnet that weathered out as brilliant little dodecahedral crystals, greasy yellow to greenish topaz in quartz veins, a very black sphalerite that collectors had mistaken for wolframite, crusts of marcasite, and an old lime kiln beside the workings.

For many decades after the mining ended, the park was a well-known source of mineral specimens. That ended in 2016, when the Trumbull Parks and Recreation Commission suspended collecting of any kind, so come to look, and leave every rock where it lies. Hiking and biking trails cross the park and carry on beyond it along a former New Haven railroad line beside the Pequonnock River, which flows through the southern part of the park. Enter from Old Mine Road on the south or Corporate Drive on the north.