FTSE 250 movers: Petra Diamonds sparkles after latest discovery

Miner Petra Diamonds has recovered an "exceptional" 122.52-carat blue diamond at its Cullinan mine in South Africa. "The rarity of a blue diamond of this magnitude sets it apart as a truly significant find," the company said in a statement. RBC Capital upped its target price from 180p to 200p, retaining an outperform rating.Oil stocks were being driven higher by the surge in the price of oil, which has hit a nine-month high amid growing fears about the situation in Iraq, a major oil producer. Ophir Energy, Wood Group, Afren, Cairn and Premier Oil were all rising stongly this afternoon. Vesuvius was lifted by Numis, which upgraded the stock from 'hold' to 'add' with a target price of 515p.Meanwhile, Bwin.party shares slumped on the news Amaya Gaming, a Canadian company, has acquired PokerStars-owner Rational Group in a deal worth $4.9bn, meaning Bwin is no longer the biggest of the listed online gaming groups. Sector peer 888 Holdings also moved sharply lower.The prospect of a sooner-than-expected rate rise in the UK pushed property stocks and housebuilders lower in today's session, as investors reacted to comments made by policymakers during the Mansion House speeches. Taylor Wimpey, Howden Joinery, Berkeley Group, Bellway and Bovis Homes were all firmly in the red. FTSE 250 - RisersPetra Diamonds Ltd.(DI) (PDL) 177.60p +6.28%Ophir Energy (OPHR) 241.30p +2.29%Wood Group (John) (WG.) 804.00p +1.77%Afren (AFR) 143.30p +1.13%Cairn Energy (CNE) 203.10p +0.79%IG Group Holdings (IGG) 579.50p +0.78%Premier Oil (PMO) 342.90p +0.53%KCOM Group (KCOM) 94.55p +0.53%Vesuvius (VSVS) 457.90p +0.31%Alent (ALNT) 343.40p +0.20%FTSE 250 - FallersBwin.party Digital Entertainment (BPTY) 104.60p -8.25%Taylor Wimpey (TW.) 103.00p -7.21%888 Holdings (888) 117.00p -6.40%Thomas Cook Group (TCG) 140.20p -6.35%Howden Joinery Group (HWDN) 309.40p -6.19%Berkeley Group Holdings (The) (BKG) 2,238.00p -6.12%Supergroup (SGP) 1,005.00p -5.46%Bellway (BWY) 1,444.00p -5.37%Bovis Homes Group (BVS) 752.50p -4.75%Crest Nicholson Holdings (CRST) 328.30p -4.67%NR