Here is an article with the details on the payout amounts and how to file your claim. Here is a statement on this suit directly from De Beers.
Recently there was also the opportunity to participate in the payout of another class action suit. This one involved credit card companies and overcharges for currency change fees. Do you take the time to look into this type of suits and find out if money is owed to you. If so, do you file a claim form or don’t bother with jumping through hoops for this?