Who is the richest diamond seller?

Could you elaborate on who exactly you mean by the term "richest diamond seller"? Is this referring to an individual, a company, or perhaps a particular organization within the diamond industry? Also, how do we determine the criteria for "richest"? Is it based on net worth, annual revenue, or some other metric? Without further clarification, it's difficult to provide a definitive answer, as there are numerous players in the diamond market with varying levels of success and financial standing. Could you please provide more specific details so that I can better understand your question and offer a more accurate response?