A survey of gypsum-bearing lakes on Eyre Peninsula has indicated a promising deposit about 10 miles SSE of Streaky Bay. Other deposits examined, namely those near Charra, Point De Mole, Lake Yaninee, Kopi, Lake Malata and Lake Greenly suffer from one or more of the disadvantages of smallness, inaccessibility and poor quality. The principal deposit near Streaky Bay is estimated, on the basis of over 78 Proline bore-holes, to contain 33 million cubic yards (about 35 million tons) of grey gypsum sand of 90% or higher purity covering 5.48 square miles to an average depth of 5.88 feet. The chief impurity is calcite, averaging 6% by weight. Higher quality gypsum sand in dunes in the same area is estimated to aggregate 520,000 tons. The deposit is within easy reach of Streaky Bay jetty where small steamers call.