Origin of black Academy Granite

The black granite known as "Black Academy" comes from the Academy pluton, a 'granite' igneous intrusion at the western edge of the Sierra Nevada mountains. The dark gray to black granite at Academy was formed by magma slowly crystallizing as it cooled below the surface of the Earth. While stone from Academy has long been known as 'black granite' in the commercial stone trade, geologically speaking the black stone from the Academy formation is actually a mafic stone and not a true granite. Academy granite is not a true 'black granite' but a gabbro. Gabbros similar to those from Academy cover about 60% of the earth's surface, mostly under the seafloors. The earth constantly produces new gabbro rocks similar to black Academy granite. These black and grey gabbros form in an ongoing geological recycling process that has replaced the entire ocean floor over the last 180 million years.

Formation of Black Academy Granite

Formed during the Jurassic Age, while dinosaurs roamed the earth, the black to dark gray granites of the Academy formation were once molten magma at the base of an ancient volcano. The magma cooled and crystallized into the black granite (gabbro). Over time, erosion reduced the stone volcano to foothills and only the erosion resistant black granite of the Academy formation remained exposed.

The Academy Granite Name

Academy granite was named for the town of Academy in Fresno County, California where this black granite was first quarried. Granite has been quarried there since the late 1800's and was used even earlier by the Yakut tribe for stone tools. Academy granite was first mined from large black granite surface boulders. Later the Academy quarries were excavated. Quarrying of the black granite increased substantially when the railroad was extended through the towns of Academy and Clovis in the early 1900's and Black Academy granite was able to be shipped nationwide.

Colors of Academy Granite

Academy granites vary from almost black to dark gray. The dark gray to black color of the granite allows for excellent contrast between polished and unpolished faces.

Academy as a Stone Cladding

StonePly bonds polished black granite to aluminum honeycomb panels or other composite backup material to form lightweight, strong and easy to install black granite panels. With up to 60 times the impact resistance of ordinary stone slabs and a weight of less than 4 lbs per square foot, StonePly makes granite cladding faster, easier and stronger.

Billions of years in the making, few materials have lasted as long or will last as long as granite. Outdoors, most polished black granites have an erosion factor of 0.125" per 1,000 years.

The StonePly process combines the incredible beauty and durability of natural black granite with the lightweight and ease of use of aluminum honeycomb. The classic black color and handsome good looks of black granite makes it an excellent choice for anywhere a beautiful, long lasting and natural building material is needed.