Questor share tip: The price is still right to stock up on Petra Diamonds The company does not have 100pc ownership of the mines because the government owns the rest, as is common practice. Petra's diamond production in the six months to December 31 rose by 63pc to 953,553 carats but the majority of this uplift was caused by the inclusion of output from Finsch from September 14. Production should be higher in the second half of the year because there will be a full six-month contribution from its recent purchase. This implies Petra is well on track to meet its guidance for the full year of 2m carats mined. Sales in the period rose 13pc to $101.4m, with the number of carats sold rising 16pc to 678,772 carats. This reflected the pricing weakness in the last three months of the year. Diamond prices are very sensitive to economic conditions - and prices plunged in the last few months of 2011 because of the unfolding eurozone crisis. Rough diamond prices have fallen from the highs reached in June 2011. However, Thanksgiving and Christmas jewellery sales registered modest growth in the US and Europe and strong growth in demand continued from emerging markets, particularly China and India. With regards to pricing, Petra said "direct observation is that the market stabilised in December 2011 and, going into 2012, the company expects this trend to continue." This is demonstrated by the high level of interest in Petra's first diamond tender of the year, which is currently under way, as well as anecdotal evidence and feedback from Petra's client base concerning current global demand for rough diamonds. Petra accepts that there could be some short-term volatility but the long-term fundamentals of the industry are "compelling." Supply is forecast to remain flat or may decline but demand for diamonds is expected to continue to rise in both established and new markets as wealth and consumer spending increases. A report released last week by consulting group and diamond industry expert Bain & Co forecast a compounded annual growth rate of diamond prices of 6.6pc between 2010 and 2020, growing to a market worth $23bn (£14.5bn) annually. "Starting in 2013, demand will likely return to its pre-crisis historical trajectory and then continue to grow steadily," Bain said. Petra plans to provide a full update on costs and capital expansion plans in its interim results, which are expected towards the end of February. The shares are trading on a June 2012 multiple of 11.9, falling to just 7.2 next year. This looks very cheap for this quality player. Named as a tip of the year at the start of January, the shares are up 13pc compared with a FTSE 100 up 4pc. The shares remain a buy.