An activated gem that gives a 10% chance to save using a charm when creating pouches when worn.
A spirit sapphire is a spirit gem used in the Summoning skill. It can be looted from certain creatures who drop single summoning charms when they die.
Worn in the pocket slot, activated spirit gems (a) have a chance to save a charm when you are creating summoning pouches with the gem equipped. When a charm is saved, a charge is removed from the gem. Once a gem runs out of charges, the gem will be destroyed. Each gem has a different number of charges and a different chance to save a charm.
The spirit sapphire gives a 10% chance that a charm will be saved, and has 10 charges.
Previously spirit gems allowed you to store a number of uncharged pouches inside them. These gems could then be taken to and used on a summoning obelisk to receive the charged pouch and the XP produced for charging a pouch of that type. The pouches that were created from these gems were in noted form. The spirit sapphire gem had 5 charges. Once the gem's charges had been used the gem was destroyed.
For players who still have these old spirit gems you will be able to click on them to convert the gem into the new type, giving your any XP that you would have got from using the gem on an obelisk.