Ancient Greece possessed ample clay deposits, in particular large quantities of high quality secondary clay. The clay deposits in Athens were distinguished by their content of iron oxide and calcium oxide, which produced the reddish-orange colour of the fired clay, while Corinthian clay typically had a creamy-white appearance. Smaller amounts of specialist clays like kaolin (kaolinite) were also available, being reserved for decorative purposes. For example, the Greeks' characteristic black metallic glaze was produced using a clay low in calcium oxide but high in iron oxides and hydroxides. After the Minoan era, Greek vases were generally made using a potter's wheel, although handmade decorative elements were added to thrown pots. Greek potters
