DEBSWANA, the 50/50 diamond mining partnership between De Beers Centenary AG and the Botswana government, has reported a 21,8% drop in revenue to 5,4 billion pula for the last financial year. The drop for the year ending December 1998 is partially attributed to a 1,7% drop in the carat weight of stones recovered, from 20,12-million carats to 19,77-million carats. Ore treated at Debswana plants also dropped marginally to 21,07-million tons from 21,09-million in 1997. Production at the group’s Jwaneng mine, which is considered to produce the highest quality stones in the world, was however up by 1,66%.