pearl ash(n = noun.substance) - an impure form of potassium carbonate;
is a kind of potassium carbonate

alpine ash, american mountain ash, arizona ash, ash, ash bin, ash cake, ash can, ash gray, ash grey, ash tree, ash wednesday, basket ash, black ash, blue ash, bone ash, brown ash, common european ash, downy ash, european ash, european mountain ash, flowering ash, fly ash, green ash, hoop ash, manna ash, mountain ash, oregon ash, pearl, pearl bailey, pearl barley, pearl buck, pearl diver, pearl fishery, pearl gray, pearl grey, pearl harbor, pearl hominy, pearl mae bailey, pearl millet, pearl oyster, pearl river, pearl sago, pearl sydenstricker buck, poison ash, prickly ash, pumpkin ash, red ash, sea ash, seed pearl, silver ash, soda ash, swamp ash, western mountain ash, white ash, white mountain ash