Book excerpt: The Balmat Mining District in southern St. Lawrence County, New York, is a former mining site known among collectors for its highly prized minerals. For more than 100 years, it was one of the world's most important sources of talc and zinc. Because most of the zinc ore was crushed underground and brought to the surface for separation, only mineral specimens brought out by miners and geologists have survived. Outstanding specimens from both the talc and zinc mines, preserved in only a few collections, are featured in this book--many for the first time. Some of the fine specimens included are hexagonite, manganocummingtonite, groutite, calcite, sphalerite, and magnetite. With more than 200 photographs, this book is the first comprehensive description of the history, geology, and mineralogy of this important mining district.