London ? A 507-carat diamond as big as a chicken’s egg sold for $35.3 million, breaking the record for the highest price ever paid for a rough diamond, the supplier said Friday.

The stone — which weighs just over 100 grams — was estimated to be among the world’s top 20 high-quality rough diamonds. It was discovered in September at South Africa’s Cullinan mine.

London-listed diamond supplier Petra Diamonds Ltd. said the gem was purchased by Hong Kong-based private jewelry retailer Chow Tai Fook Jewelry Co. Ltd.