Overworld Quartz Mod 1.8, 1.7.10, 1.7.2 adds quartz into to the overworld. It's fully multiplayer compatible, and available for 1.6.4 through 1.8!

Quartz from the overworld requires a Stone pick or higher, and has the same spawn rate as iron ore. It drops 1 nether quartz per ore block. If mined with Silk Touch, you can smelt the ore into nether quartz.