I had no luck pushing or parrying them into a pit so just had them chase me into a raised terrain enclosure. Rapidly jumped up an interior ladder (which golem quickly destroyed) and filled in the opening before it got wise and left. Leveling skill against a live opponent is not quite the same as continuously striking a rock to get same. The game may or may not allow the frost staff to damage a stone golem but there are other opponents that are likewise immune to various damage types. If the game eventually releases a Staff of Poison then using it against a trapped Bonemass would be equally viable.