f019253d_The_Delaware_Geological_Survey_inerals_of_the_Red_Clay_Valley_Description
[Rock Type] Serpentine [Description] 
A secondary mineral that forms by the alteration of magnesium-rich minerals. Serpentines are always shades of green, they are soft, and have a slightly soapy or greasy feel
Common Rocks and Minerals of the Delaware Piedmont | The Delaware Geological Survey
Description