A creative way that someone found to get the item is to set the map on fire by using various methods to set a fire on the map. The weapon itself is made of rubynus, which is fireproof. If your fire resistance is high enough that your own stuff won't get burnt, you can sit in the middle of the map while the sisters burn up around you. If you don't want to go around and check piles of equipment, or look for a precious item sparkle. you could just save occasionally, which would update your art.log. This would tell you if the artifact had been generated or not.