Unfortunately, eastern Pa. was not blessed with the high quality lithics of ,say,the Ohio valley....Compressed shales,Argillite, Rhyolite did not hold up as well as Quartzite or Jasper which is why artifacts made from these materials , especially Quartzite, are often found more intact than artifacts made from the compressed "mud"....I have found literally thousands of artifacts made from all kinds of material, and quartzite arrowheads are commonly undamaged compared to the rest.