Place Quartz in a Furnace with Coal
Place Fire Quartz in a Furnace with Coal
Place Frozen Tear in a Furnace with Coal
Place Earth Crystal in a Furnace with Coal
Recycle broken CDs and broken glasses with a Recycling Machine for Quartz, then smelt it into Refined Quartz
Fish up Quartz from treasure chests and smelt it into Refined Quartz
Buy Quartz from Krobus on Wednesdays and smelt it into Refined Quartz
Buy Quartz from the Desert Trader on certain days and smelt it into Refined Quartz
Use the Geologist profession to help gather more Quartz sources for smelting
Use the Crystalarium to duplicate Quartz, then smelt the copies into Refined Quartz