taken from arreat summit

3 Thul Runes + 1 Chipped Topaz = Amn Rune
3 Amn Runes + 1 Chipped Amethyst = Sol Rune
3 Sol Runes + 1 Chipped Sapphire = Shael Rune
3 Shael Runes + 1 Chipped Ruby = Dol Rune

The following Rune upgrade formulae will only work for Single-Player, Open, or Ladder Characters. They will not work for Normal Characters on the Realms:

3 Dol Runes + 1 Chipped Emerald = Hel Rune
3 Hel Runes + 1 Chipped Diamond = Io Rune
3 Io Runes + 1 Flawed Topaz = Lum Rune
3 Lum Runes + 1 Flawed Amethyst = Ko Rune
3 Ko Runes + 1 Flawed Sapphire = Fal Rune
3 Fal Runes + 1 Flawed Ruby = Lem Rune
3 Lem Runes + 1 Flawed Emerald = Pul Rune
2 Pul Runes + 1 Flawed Diamond = Um Rune
2 Um Runes + 1 Topaz = Mal Rune
2 Mal Runes + 1 Amethyst = Ist Rune
2 Ist Runes + 1 Sapphire = Gul Rune
2 Gul Runes + 1 Ruby = Vex Rune
2 Vex Runes + 1 Emerald = Ohm Rune
2 Ohm Runes + 1 Diamond = Lo Rune
2 Lo Runes + 1 Flawless Topaz = Sur Rune
2 Sur Runes + 1 Flawless Amethyst = Ber Rune
2 Ber Runes + 1 Flawless Sapphire = Jah Rune
2 Jah Runes + 1 Flawless Ruby = Cham Rune
2 Cham Runes + 1 Flawless Emerald = Zod Rune

What is this!?! A center for ants!?