in Ocean and Beach biomes at any depth.<~><~>  Nether Quartz Gems are connected to Infernal magic and can be Netherrack in the Nether.<~><~>  Opal Gems are connected to 
ycelimantic magic and its ore can be found in Mud.<~><~>  Onyx Gems are connected to Necromantic magic and its ore can be found in Swamp biomes at depths between 0 and 60 
blocks from Bedrock.<~><~>  Smoky Quartz Gems 