Make your own plaster artifacts for students to "play" with in your classroom social studies or art center. Step-by-step directions walk you (or a parent volunteer) through the 10-30 minute process required to make each of the following artifacts:
*plaster mortar and stone pestle (you supply the stone pestle), strong enough for grinding
*plaster "rock" that students can carve into a stone bowl
*sample plaster petroglyphs
*replica of the oldest petroglyphs on earth--cupules foun