You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
Lets say for whatever reason, the giant Diamond fields of South Africa are exploited by many competitive firms.
There is no Diamond monopoly and no big marketing campaign that turns them into the most wanted gem.
(some short interesting points: http://www.wanderings.net/notebook/Main/10ReasonsWhyYouShouldNeverBuyDiamonds)
Now, how cheap would diamonds be? And the most important question, how would affordable diamonds change industry, consumer goods, basically the non luxury market?