It gives a 50% chance to save a charm when it is worn while creating summoning pouches. It has 50 charges and loses a charge for every charm it saves. When all the charges are consumed, it breaks. Once equipped, it becomes a spirit dragonstone (a) and does not stack with other gems in the bank. Combining these gems will consolidate the charges into one gem. Additionally, 3 of them can be forged together to create one spirit onyx, resulting in a net loss of 90 possible charms, but a 60% chance to save a charm opposed to 50%.