f019253d_The_Delaware_Geological_Survey_inerals_of_the_Red_Clay_Valley_Description
[Rock Type] Calcite and Dolomite [Description] 
The major minerals in marble. In the Delaware Piedmont they occur in the Cockeysville Marble as blue-white, coarsely crystalline interlocking grains. Years ago the marble was quarried, converted into quick lime, and used as a soil conditioner.
Common Rocks and Minerals of the Delaware Piedmont | The Delaware Geological Survey
Description