Runestones

Runestones allow you to customize skills by changing the way they look, sound, and how they function.

There are five runestone types: Crimson, Indigo, Obsidian, Golden, and Alabaster. Each runestone affects skills differently. For example, adding a Crimson Runestone to a skill may enhance its damage, while adding an Alabaster Runestone might add a stun effect.

See the full runestone systems preview at Diablo3.com