This beautiful memorial entrance sign to St. Mary's Cemetery on Route 56, Potsdam, is made of red Hopkinton sandstone. Of the original four sandstone quarries in Hopkinton, this is the only one that has red sandstone. The owners have begun selling this beautiful sandstone in limited amounts at this time. The original stone cutting of this quarry began as early as 1808. Mary Converse, Town of Hopkinton Historian.