|Diamond and jewelry tycoons had a mixed year, according to the annual Forbes list of billionaires.
Nicky Oppenheimer and family dropped to No. 182 on the list calculated to March 2013 from No. 136 in 2012, with their net worth plummeting by US$300 million to US$6.5 billion. The Oppenheimer sold their stake in De Beers to Anglo American for just over US$5 billion in 2011.
Israeli diamond tycoons Beny Steinmetz and Lev Leviev both recorded steep falls in their wealth.
Steinmetz now finds himself at No. 316 from No. 162 last year, with his net worth at US$4.1 billion from US$5.9 billion. He is estimated to be the sixth-richest man in Israel.
Meanwhile, Leviev was placed at 974 from 764th place last year with his net worth plunging by US$200 million to US$1.5 billion. Leviev is the 12th richest person in Israel, according to Forbes.
In the jewelry world, Bernard Arnault, the chairman of LVMH Moėt Hennessy Louis Vuitton, the world's biggest luxury goods group, fell to 10th place from fourth last year with a net worth of US$29 billion.
Among other luxury goods figures, Johann Rupert of Richemont and family was ranked No. 179 with a net worth of US$6.6 billion, while PPR Chairman Francois Pinault and his family were placed at No. 53 with a net worth of US$15 billion.
British jeweler Laurence Graff, increased his standing on the list, rising 160 places to No. 299 with a net worth of US$4.3 billion, up from US$2.6 billion last year.
The United States has the largest number of super-rich on the Forbes list with 442 billionaires, while the Asia-Pacific region has 386, Europe has 366, the Americas has 129, and the Middle East and Africa have 103.