Black Opal is a Super Rare Gem in Coral Island. While it is not used in any essential recipes, you still need this gemstone to complete a main quest — and to help Scott find all the missing artifacts for the Museum. The only challenge is that, unlike other minerals, Black Opals are not easy to find. There seems to be heavy RNG involved in their spawns, and many beginner players don’t even know where to look for one. In this guide, you will learn everything about this precious stone and figure out the best methods for farming Black Opals.