Paul, the speckled (porphyritic) is grainer and harder to work than the green stuff. The specks are phenocrysts of feldspar, quartz, or pyrite in some varieties. It works pretty good with wood. You can make nice bigger points from it, but it's not as good for smaller stuff. Most of the Savannah River, Stanley, and Guilford points in central NC were made from the speckled stuff.