View source for Custom Spell Gem Engraving

Myths of Atalan employs a custom crafting system that includes enchanting gemstones to be used much the same way scrolls are. Unlike scrolls, gems cannot be used by wizards to learn spells from. However, enchanted gems have multiple uses before the magical energies will cause them to fracture. Rune Stones reflect caster level and metamagic increases. The gems used for this process are the same as those used for scribing scrolls.
 
(See [[Custom Scroll Scribing]] for the list of gems and their spell containment power.)

To Create a Rune Stone you must Scribe an Enchanted Gem at the Gem Detailing Table using the CNR, and then cast the appropriate spell on the new Scribed Gem Stone.

Each Rune Stone can be used once per day, and can be used at least twice before it breaks. Each time you use the rune it adds a 25% chance of breaking, and each time it rolls vs the break chance to see if it broke (breaking does not prevent it from working on that time). So first time is 0% break chance, second is 25%, 3rd is 50%, 4th is 75% and if you make it to the mythical 5 uses it has a 100% chance of breaking.