When did De Beers miner discover the diamond?

According to Wikipedia:

"Cecil Rhodes, the founder of De Beers, got his start by renting water pumps to miners during the diamond rush that started in 1871, when an 83.5 carat diamond was found on Colesburg Kopje (present day Kimberley), South Africa. He invested the profits of this operation into buying up claims of small mining operators, with his operations soon expanding into a separate mining company."

Diamonds were first 'discovered', however, about 6,000 years ago, and not by De Beers. The De Beers organization simply capitalized on mining diamonds in South Africa. It is believed that diamonds were first 'discovered' in India.