f019253d_The_Delaware_Geological_Survey_inerals_of_the_Red_Clay_Valley_Description
[Rock Type] Garnet [Description] 
Most Piedmont garnets are a dark-red, iron-rich variety called almandine. They usually occur as 12-sided crystals that vary in size from crystals so small they can be seen only under a microscope to crystals of an inch or more across. Garnets are considered semi-precious stones, but in the highly deformed rocks of the Piedmont they are usually fractured and not suitable for jewelery. Garnet is also used as an abrasive.
Common Rocks and Minerals of the Delaware Piedmont | The Delaware Geological Survey
Description