This rare 122.52ct blue diamond has been discovered at the famous Cullinan mine in South Africa and will go on sale at the end of this month. The actual stone is the size of a strawberry and weighs the equivalent to three pound coins. The rare blue stone is reportedly worth more than £60 million. The Cullinan mine in South Africa is renowned for producing some of the most rarest and famous diamonds with a blue diamond fetching £508,000 at the start of this year, which gives this stone hope of exceeding the record selling price for rare blue diamond’s like this. According to experts this stone will be extremely popular amongst buyers as its apparently unheard of to find a blue stone that weighs over 100 carats. The stone was discovered by the diamond company Petra Diamonds, whose shares increased by 8% after the discovery – adding £66 million to the value of the value of the company in just one day. The blue colour in the diamond is extremely rare and comes from small amounts of boron which is trapped in their crystal structure and the more blue in colour, the greater the value of the stone.