Michelangelo used Carrara marble for three reasons.
First, calcite is a soft mineral, which makes it easy to carve. Second,
the calcite crystals in the Carrara marbles are very small. This also
makes carving easier. More important, it makes the finished statue look
more lifelike. Finally, the Carrara marbles are pure in color, which
makes the statues more beautiful.
The Carrara limestone quarries are still open.
Modern sculptors still use the same marble as Michelangelo.
Carrara quarries, Italy
Outcrop of Carrara Marble