WHICH IS MO PRECIOUS DIAMOND OR EMERALD ON MINECRAFT?

Well I mean emeralds can be traded for different items through villagers, but diamond can make weapons, armor, and more, so… Redstone!

Diamond because it had more uses

To me, emeralds are more valuable. Although emeralds are rarer at the start, it can get pretty common once you have found a village. You can start an infinite villager breeding farm and start trading to find your perfect villager. When you've found a couple of perfect villagers, emeralds become common. This is due to the villager having trades for items that are easily farmed like paper or iron ingots for emeralds and you can basically use the emeralds to trade with villagers to get whatever you want, even rare diamond tools. So you don't have to waste time looking for diamond.