Petra Diamonds Regulatory News (PDL)

8 Oct 2007 07:01

Petra Diamonds Ld08 October 2007 For release 8 October 2007 AIM: PDL Petra Diamonds Limited South Africa - substantial increase in Reserves and Resources Petra Diamonds ("Petra" or "the Company" or "the Group") announces an updatedstatement of the Group's South African reserves and resources. The statement hasbeen prepared in accordance with JORC and is in respect of the Koffiefontein,Helam, Sedibeng and Star mines. Highlights • Updated carat base of 9.33 million carats attributable (11.38 million carats gross), an increase of 101% on previous statement (May 2005: 4.64 million carats attributable) • In-situ value of US$1.5 billion attributable (US$1.9 billion gross) • JORC compliant attributable reserves increase 66% to 2.95 million carats (May 2005: 1.77m carats) • JORC compliant attributable resources increase 123% to 6.38 million carats (May 2005: 2.86m carats) • Increase due to the acquisition of Koffiefontein and additional kimberlite fissure units included in the total mineral resource SUMMARY OF ATTRIBUTABLE RESERVES AND RESOURCES COMBINED SOUTH AFRICAN OPERATIONS Contained Contained Tonnes Grade Diamonds Diamonds MayCategory October 2007 October 2007 October 2007 2005 (millions) (cpht) (millions) (millions)Ore/Diamond reservesProven 18.397 8.3 1.524 0.558Probable 1.993 71.3 1.422 1.217Sub-total 20.390 14.5 2.946 1.775Diamond resourcesMeasured 40.674 2.9 1.169 - *Indicated 12.774 9.5 1.218 - *Inferred 31.036 12.9 3.994 2.864Sub-total 84.484 7.6 6.381 2.864Total 104.874 8.9 9.327 4.639 * Refer to Note 4 below regarding the treatment of measured and indicatedresources of the fissure mines. The resource statement, in compliance with the AIM Guidance for MiningCompanies, is shown below in total for the Group's South African operations andthen shown split out as to Koffiefontein and the fissure mines (Helam, Sedibengand Star combined). This statement does not include any contribution fromKimberley Underground which will only form part of Petra's assets when theconditions in the corresponding acquisition agreement are met. SUMMARY OF RESERVES AND RESOURCES BY STATUS - COMBINED SOUTH AFRICAN OPERATIONS Category Gross Net attributable Operator Tonnes Grade Contained Tonnes Grade Contained (millions) (cpht) Diamonds (millions) (cpht) Diamonds (millions) (millions)Ore/Diamondreserves perasset Proven 25.860 7.3 1.886 18.397 8.3 1.524 Refer summaries belowProbable 2.105 69.0 1.453 1.993 71.3 1.422 Refer summaries belowSub-total 27.965 11.9 3.339 20.390 14.5 2.946 Diamondresources perasset Measured 58.105 2.9 1.670 40.674 2.9 1.169 Koffiefontein JV Indicated 18.248 9.5 1.740 12.774 9.5 1.218 Refer summaries belowInferred 43.787 10.6 4.632 31.036 12.9 3.994 Refer summaries belowSub-total 120.140 6.7 8.042 84.484 7.6 6.381 Total 148.105 7.7 11.381 104.874 8.9 9.327 SUMMARY OF RESERVES AND RESOURCES BY STATUS - KOFFIEFONTEIN Category Gross Net attributable Operator Tonnes Grade Contained Tonnes Grade Contained (millions) (cpht) Diamonds (millions) (cpht) Diamonds (millions) (millions)Ore/Diamondreserves perasset Proven 24.436 4.4 1.080 17.105 4.4 0.756 Koffiefontein JV Probable - - - - - - Sub-total 24.436 4.4 1.080 17.105 4.4 0.756 Diamondresources perasset Measured 58.105 2.9 1.670 40.674 2.9 1.169 Koffiefontein JV Indicated 18.248 9.5 1.740 12.774 9.5 1.218 Koffiefontein JV Inferred 42.263 4.6 1.960 29.584 4.6 1.372 Koffiefontein JV Sub-total 118.616 4.5 5.370 83.031 4.5 3.759 Total 143.052 4.5 6.450 100.136 4.5 4.515 Koffiefontein; reserves and resources have been taken from De Beers June 2005internal scorecard classification (considered to be a conservativeclassification) and depleted by mining conducted by De Beers from July 2005 toMarch 2006 and by Petra to September 2007. Reserves and resources have beenre-classified in compliance with JORC 2004. SUMMARY OF RESERVES AND RESOURCES BY STATUS - FISSURE MINES COMBINED (HELAM, SEDIBENG, STAR) Category Gross Net attributable Operator Tonnes Grade Contained Tonnes Grade Contained (millions) (cpht) Diamonds (millions) (cpht) Diamonds (millions) (millions)Ore/Diamondreserves perasset Proven 1.424 56.6 0.806 1.292 59.5 0.768 Petra/Sedibeng Mine JVProbable 2.105 69.0 1.453 1.993 71.3 1.422 Petra/Sedibeng Mine JVSub-total 3.529 64.0 2.259 3.285 66.7 2.190 Diamondresources perasset Measured - - - - - - Indicated - - - - - - Inferred 1.524 175.3 2.672 1.452 180.6 2.622 Petra/Sedibeng Mine JVSub-total 1.524 175.3 2.672 1.452 180.6 2.622 Total 5.053 97.6 4.931 4,737 101.6 4.812 Fissure mines; grades and fissure widths are extrapolated downwards belowworking levels from detailed historical records collected over many decades ofmining, with confirmation of fissure continuity by diamond drilling wherenecessary. For further information, please contact:Justine Howarth / Louise Goodeve Telephone: +44 (0) 20 7851 7480Parkgreen Communications, London Adrian Hadden Telephone: +44 (0) 20 7523 8000Collins Stewart, London Ends Notes 1. The information in this update that relates to Exploration Results, MineralResources or Ore Reserves is based on information compiled by Jim Davidson, Pr.Sci Nat (reg No 400031/06), who is a Member of the Geological Society of SouthAfrica, a 'Recognised Overseas Professional Organisation' ('ROPO'). Jim Davidsonis the Qualified Person for the purposes of the AIM Guidance Note on Mining, Oiland Gas Companies dated March 2006. Jim Davidson is a full-time employee of theCompany and has sufficient experience which is relevant to the style ofmineralisation and type of deposit under consideration and to the activity whichhe is undertaking to qualify. Jim Davidson has given his written consent to theinclusion in this announcement of the matters based on his information in theform and context in which it appears. 2. "Operator" is name of the company that operates the asset; "Gross" are 100%of the reserves and/or resources attributable to the licence whilst "Netattributable" are those attributable to the AIM company; "cpht" is carats perone hundred tonnes. 3. The previous JORC compliant statement of resources and reserves published byPetra was dated 26 April 2005. It was prepared by Snowden Mining IndustryConsultants ("Snowden") as part of the documentation required when Petra mergedwith Crown Diamonds NL in May 2005. At that time the resources and reserves wereonly in respect of the Helam, Sedibeng and Star fissure mines. The currentreserves and resources have been updated using the same parameters applied asper the Snowden 2005 report. 4. Fissures - measured resources are classified as one level below the base ofthe deepest workings, indicated resources as two levels below the base of themeasured resources, and inferred resources as three levels below the base of theindicated resources. Measured and indicated resources have been converted toproven and probable reserves by applying historically derived waste rockdilution and in-stope loss factors to in-situ kimberlite tonnages and grades.Resources converted to reserves have been subtracted from the overall resourcefigure and reported separately. Due to in-stope loss factors of 10% forshrinkage mining (carried out at Helam and Sedibeng), reserve carats will beless than resource carats on conversion and this adjustment has been included inthe statements above. Glossary "mineral resources" - a concentration or occurrence of material of intrinsiceconomic interest in or on the earth's crust in such form, quality and quantitythat there are reasonable prospects for eventual economic extraction. "inferred mineral resource" - that part of a mineral resource for which tonnage,grade and mineral content can be estimated with a low level of confidence. It isinferred from geological evidence and assumed but not verified geologically and/or through analysis of grade continuity. It is based on information gatheredthrough appropriate techniques from locations such as outcrops, trenches, pits,workings and drill holes which may be limited or of uncertain quality andreliability. "indicated mineral resource" - that part of a mineral resource for whichtonnage, densities, shape, physical characteristics, grade and mineral contentcan be estimated with a reasonable level of confidence. It is based onexploration, sampling and testing information gathered though appropriatetechniques from locations such as outcrops, trenches, pits, workings and drillholes. The locations are too widely or inappropriately spaced to confirmgeological and/or grade continuity but are spaced closely enough for continuityto be assumed. "measured mineral resource" - that portion of a mineral resource for whichtonnage, densities, shape, physical characteristics, grade and mineral contentcan be estimated with a high level of confidence. It is based on detailed andreliable exploration, sampling and testing information gathered throughappropriate techniques from locations such as outcrops, trenches, pits, workingsand drill holes. The locations are spaced closely enough to confirm geologicaland/or grade continuity. "ore reserves" - those portions of mineral resources which, after theapplication of all mining factors, result in an estimated tonnage and gradewhich, in the opinion of the competent person making the estimates, can be thebasis of a viable project, after taking account of all relevant modifyingfactors. "probable ore reserve" - the economically mineable part of an indicated, and insome circumstances measured mineral resource. It includes diluting materials andallowances for losses which may occur when the material is mined. Appropriateassessments and studies have been carried out, and include consideration of andmodification by realistically assumed mining, metallurgical, economic,marketing, legal, environmental, social and governmental factors. Theseassessments demonstrate at the time of reporting that extraction couldreasonably be justified. "proven ore reserve" - the economically mineable part of a measured mineralresource. It includes diluting material and allowances for losses which mayoccur when the material is mined. Appropriate assessments and studies have beencarried out, and include consideration of and modification by realisticallyassumed mining, metallurgical, economic, marketing, legal, environmental, socialand governmental factors. These assessments demonstrate at the time of reportingthat extraction could reasonably be justified. This information is provided by RNS The company news service from the London Stock Exchange