I found this rock in Smithfield NC. It does scratch glass. A butter knife didn’t scratch it. When you hold it to a light it has an orange glow. It didn’t leave anything on porcelain.
Looks like Quartz (massive transparent/translucent crystal or rock without cleavages and hardness of 6) with iron oxyhydroxide coating, hence the red color. Could also be feldspar there, and then it would be an alkali granite. Most likely product of a late magmatism, as a vein or something similar. (if my identification is correct)
This is a quartz vein that has strong microfracturing and moderate hematite alteration. The fractures are filled in with hematite-rich fluids, which accounts for the red color. This is a good example of fluids filling in microfractures, which is a very common process in rock mechanics. The fracture-filling process occurs at depth within the earth's crust during the rocks formation.