BALL-VEIN, in Mineralogy, a name given by the miners of Sussex to a sort of iron ore common there, and wrought to considerable advantage. It yields not any great quantity of metal, but what it has runs freely in the fire; it is usually found in loose masses, not in the form of a stratum, and is often covered with one or more crusts. It generally contains some sparkling particles; and is usually of a circular form in the perfect masses, thickest in the middle, and gradually thinner as it approaches the sides. The ores of Sussex in general are poor, but they require very little trouble in the working; so that a considerable profit is made annually from them.