Alto Cuilo

Petra Diamonds Ld
20 December 2006

For Release 20 December 2006



                             Petra Diamonds Limited



                        Alto Cuilo; Bulk Sampling Update





Petra Diamonds Limited ('Petra'), the AIM-quoted and ASX-listed diamond mining
group, announces an update with regards to the bulk sampling campaign at project
Alto Cuilo ('Alto Cuilo') in Angola. The bulk sampling campaign is an important
part of the exploration programme at Alto Cuilo as it will provide key data
relating to grade and value per carat.





Highlights

  • The first microdiamond results from representative drill cores sent for
    external specialist analysis have given encouraging microdiamond counts
  • Ongoing laboratory analysis of drill core from additional kimberlites
    continues to give diamond indicator mineral chemistry ('minchem') results
    consistent with some of the world's  economic kimberlites
  • Taking into account the minchem results available to date, the ranking of
    kimberlites has been revised for the large diameter ('LD') drilling campaign
    which is underway
  • Core drilling at Alto Cuilo continues at the same time as the LD drilling
    programme and has made further solid progress, with the discovery to date of
    71 kimberlitic occurrences (31 October 2006: 62 occurrences) out of 80
    targets drilled, an exceptional success rate



Bulk sampling

A second technical target prioritisation meeting was recently held where all
minchem results received to date were tabled and kimberlites re-prioritised for
LD drilling.



The revised ranking is as follows:
Kimberlite         Current Ranking    Previous Ranking   Surface area (hectares) estimated from
                                                         aeromagnetic signatures
                   (20.12.06)         (20.6.06)
AC 63              1                  -                  20
AC 60              2                  1                  30
AC 98              3                  2                  175
AC 71              4                  -                  32



To date, 71 kimberlites have been intersected and the minchem results received
in respect of 35 of those kimberlites. The minchem results received for certain
of the kimberlites recently analysed have highlighted new occurrences of high
interest.



It is significant to note that where there is corresponding microdiamond data
for representative kimberlite material (the lead time for microdiamond analysis
being much longer than that for the minchem analysis), the microdiamond data
corroborates the minchem result. For AC63 and AC98, which have been highly
ranked on minchem, the microdiamond results are also encouraging and
correspondingly kimberlites with poor minchem have also reported a poor
microdiamond result.  Based on the relationship between minchem and microdiamond
results, AC63 has now been ranked as priority number 1 in the LD drilling
campaign. As more results are accumulated, revisions to the priority rankings
can be expected.



Drilling at AC16, the first kimberlite to be accessed by the LD drill rig, has
been successfully completed. Eight sites were successfully drilled to depths in
excess of 350 metres. All samples have been stockpiled and await commissioning
of the 10 tonne per hour Dense Media Separation ('DMS') sampling plant later
this month.



On completion of the LD drilling at AC16, the drill rig was serviced and
calibrated by a Prakla engineer and relocated and set up at AC63, where drilling
commenced last week. Although AC16 has now been relegated in priority with
regards to minchem data and does not now rank in the top as a high priority
target, it was drilled first as the LD drill needed to be tested on a kimberlite
that offered straightforward logistical conditions and good infrastructural
location to ensure proper commissioning, learnings and operational testing.



Ends





Notes

1. The information in this update that relates to Exploration Results, Mineral
Resources 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 South
Africa, a 'Recognised Overseas Professional Organisation' ('ROPO'), included in
a list promulgated by the ASX from time to time. Jim Davidson is a full-time
employee of the Company and has sufficient experience which is relevant to the
style of mineralisation and type of deposit under consideration and to the
activity which he is undertaking to qualify as a Competent Person as defined in
the 2004 Edition of the 'Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves'. Jim Davidson has given his written consent
to the inclusion in this announcement of the matters based on his information in
the form and context in which it appears. Jim Davidson is the Qualified Person
for the purposes of the AIM Guidance Note on Mining, Oil and Gas Companies dated
March 2006



2. It should be noted that the potential quantity in this report is conceptual
in nature, there has been insufficient exploration to define a Mineral Resource
and it is uncertain if further exploration will result in the determination of a
Mineral Resource.





For further information, please contact:

 Parkgreen Communications, London

Cathy Malins / Annabel Leather

Tel [phone]


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