corundum, China.12, geology.11, gems

The sapphire deposit at Penglai, on Hainan Island, is potentially the largest in China. Gem-quality sap-phires, at least one as large as 35.5 ct, have been found in alluvial gravels approximately 2 k m south-east of the city of Penglai. Gem-quality zircon and a few pieces,of, what might be considered ruby have also been recovered in the course of the geologic study of this area, which has not yet been commer-cially developed. The average size of the sapphires is 2-5 mm. They are similar in appearance and gemological properties to sapphires from Australia, Thai-land, and Kampuchea.