Chaos Emerald - Nature Green

When this artifact enters the battlefield, you can either search your library for a basic land card and put it onto the battlefield tapped or put a land card from your hand onto the battlefield.

Equipped Creature gets "{t} add one mana of any color, if you control 3 other emeralds, add two mana of any colors"
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)