New York State Academy of Mineralogy (NYSAM)

Minerals of the Adirondack Highlands

When continental plates collided with proto-North America during the Grenville Orogenic Cycle around 1.3 to 1 billion years ago, they formed a long chain of mountains which includes the dome-like uplifted region called the Adirondack Mountains.

The Adirondack Mountains are morphologically and geologically divided into the Adirondack Highlands and the Adirondack Lowlands by a wide zone of deformation called the Carthage-Colton Mylonite Zone. The Adirondack Highlands contained igneous rocks such as anorthosites, gabbros, and granites, as well as, sedimentary rocks and iron and titanium deposits. All of these rocks were metamorphosed 1090 to 1050 million years ago to granulite facies at a depth of around 25 kilometers and a temperature of 750Ã�° C. A complex interaction of the igneous, metamorphic, and hydrothermal geological processes shaped the Adirondack Highlands and generated a plethora of minerals. The finest examples of these minerals from the State Museum's collection are featured in this display case.

The Academy of Mineralogy is a not for profit organization dedicated to promoting a greater understanding and appreciation of the minerals and mineralogy of New York State. The chief goals of the organization are to work with the New York State Museum to promote the study of New York State's mineralogy and to facilitate the gathering of exceptional individual specimens and outstanding collections for preservation in the New York State Museum.