Its chief mineral products are coal, nitre, sulphur, alum, soda, saltpetre, gypsum, porcelain-earth, pipe-clay, asphalt, petroleum, marble and ores of gold, silver, mercury, copper, iron, lead, zinc, antimony, cobalt and arsenic. The principal mining regions are Zsepes-Giimor in Upper Hungary, the Kremnitz-Schemnitz district, the Nagybanya district, the Transylvanian deposits and the Banat.
The kaolin may be washed away from its original site, and deposited in hollows or lakes to form beds of white clay, such as pipe-clay; in this case it is always more or less impure.
Yellow and pinkish varieties of china-clay and pipe-clay contain a small quantity of oxide of iron.
