Gemwords for leveling

Monkey Head
Ruby + Skull
2 Socket Helm
Hit Causes Monster to Flee 12-25%
+50 To Life
Replenish Life +6, Regenerate Mana 24%
+2 To Light Radius

Prism
Perfect Ruby + Perfect Sapphire + Perfect Emerald + Perfect Topaz + Perfect Amethyst+ Perfect Diamond
6 Socket Weapon
+20% Increased Attack Speed
+180 Magic Damage
Ignore Target’s Defense
+15-20 Fire Damage
+10-14 Cold Damage, 3.0 sec Duration
+1-40 Lightning Damage
+100 Poison Damage over 7 Seconds
+68% Damage vs. Undead
+150 to Attack Rating
+12 To Light Radius

I could actually see gems being treated as runes for the purpose of new runewords, either through rune+gem combinations, or through, indeed, gems only.
I don’t think it will ever actually appear in the game, but from a design standpoint, there’s nothing wrong with the concept.
PS :
Gems would have to be treated as low level runes, though, for balance purposes.