In Minecraft: Gold is common, and there's no real value to it. Pure gold however is a far more valued resource.

Pure gold is refined from 8 gold ingots and flux (Ratio 8:1), this makes it 8x more valuable than normal gold.

Pure gold has a number of uses, It can make expensive golden apples and powered rails, in total: costing less to create. It is also needed for dragonforge steel and guilded armours.