Power Crystal
Power Crystals are items used to craft Golems. They weigh one stone each and cannot be stacked. When placed on the ground, they glow softly.
A tinker can craft Arcanic Rune Stones with 90 tinkering and 80 magery from 5 Power Crystals and 1 Crystal Shards.
Two NPCs, Sledge the Versatile and Wexton the Apprentice, have been known to show an interest in these items.
A Power Crystal is worth 100 Clean Up Britannia points.