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Mount Rushmore is carved out of the granite face of the Black Hills in South Dakota.
Actually, Mount Rushmore is made up of granite.
Mount Rushmore is carved out of the granite face of the Black Hills in South Dakota.
The material that makes up Mount Rushmore is granite.
Granite.
The Mount Rushmore Memorial is carved out of granite, part of the Harney Peak granite batholith that forms the Black Hills.
450,000 was removed from mount Rushmore, and 90% by dynomite
Because the mountain that they are made on is granite.
Granite and Mica Schist.
The rock in which the facs are carved is granite.
Carving was done by using dynamite to blast away more than 90% of the rock. Once there was about 3 to 6 inches of rock left to remove, they used a technique called "honeycombing", drilling holes very close together, which weakened the granite so that it was easier to remove. After the honeycombing, the granite was smoothed with a hand facer or a bumper tool, creating a surface as smooth as sidewalk.
Granite is a non-permeable, hard, and very dense igneous rock with an interlocking crystalline structure. The granite site selected also had few fractures and cracks which could lead to mechanical weathering.