Quarrying has been carried out in the extraction of Hamilton Black since the 13th century and continues today.  Hamilton Black is not a true marble but a black limestone that is speckled with the remains of prehistoric plants and marine creatures to include fossilized horn coral.  

The rock dates from the carboniferous period, some 325 million years ago. When cut and polished, Hamilton Black marble forms an attractive and ornate stone,  that was once prized throughout the UK, a good example can be found in Durham Cathedral which has some fine interior columns.

From De Ferranti's Rare Marble Collection