This stone was the first used in Deerfield, Massachusetts, at the mill erected on the Mill River between 1689 and 1692. The water-powered mill operated until 1699. The stone was quarried at Mt. Tom, to the south of Deerfield, and sold to the town in 1693, by Major John Pynchon of Springfield, Massachusetts. This millstone is an aggregate (containing smaller stones compressed into it.) Invisible in this photograph and barely detectable even up close, are grooves worn down from decades of wear. The stone was suspended just above another similar grooved stone. Grain was poured through a hopper above the stones. As the top stone turned, the sharp edges of the grooves acted like scissors blades to grind the grain.