Firestone Diamonds - Encouraging Results from MK1


RNS Number:6156O
Firestone Diamonds PLC
25 February 2008


Firestone Diamonds plc


Encouraging results from MK1 kimberlite, Tsabong


LONDON: 25 February 2008


Firestone Diamonds plc, ('Firestone' or 'the Company'), the AIM-quoted diamond
mining and exploration company (ticker: AIM:FDI), today announces an update on
evaluation work on the MK1 kimberlite at its Tsabong project in Botswana. The
Tsabong kimberlite field contains 83 kimberlites, including the 180 hectare MK1
kimberlite, which is one of the largest diamondiferous kimberlites in the world.


HIGHLIGHTS


* Positive microdiamond samples from first core hole indicate
potential for significant mineralisation


* Initial grade estimate of 20 carats per hundred tonnes


* Preliminary volumetric modeling indicates 1.1 billion tonnes of
kimberlite to 1,000 metres


* Two additional core holes completed for additional microdiamond
sampling


* Bulk sampling for macrodiamonds to commence shortly


Philip Kenny, CEO of Firestone Diamonds, commented: 'This is a highly
encouraging result from the first kimberlite to be evaluated by Firestone in the
Tsabong field, particularly given the very large size of MK1. We have 83
kimberlites in our licence area and with 14 high interest kimberlites to be bulk
sampled in 2008 and bulk sampling expected to commence in March, we believe that
the prospects for a significant economic discovery are good.'


Microdiamond recovery completed

Following the completion of a 508 metre deep core hole into MK1 in mid 2007,
samples of kimberlite from various depths were submitted to SGS Minerals
Services in Canada for microdiamond recovery. A total of 117 microdiamonds
(greater than 0.075 mm) have been recovered from the 561 kilogrammes of
kimberlitic core treated. Details of the samples and diamonds recovered are
provided in the table below:

Sample number Rock Sample weight (kg) Microdiamonds Stones per Stones per
Type recovered tonne 20 kg
MK1/1 VK 146 14 96 1.9
MK1/2 VK 187 15 80 1.6
MK1/3 VK 148 26 175 3.5
MK1/4 VK 79 62 785 15.7
Total 561 117 208 12.5


Note: VK = Volcaniclastic Kimberlite


Grade estimate

The size frequency distribution of the microdiamonds recovered has been analysed
by an independent consultant, Mr. Tinus Oosterveld, in order to provide an
indication of potential grade. Mr. Oosterveld was instrumental in establishing
the principles of grade estimation based on microdiamond size frequency
distribution during his 30 years at De Beers, and is considered to be one of the
leading experts in the field.


The initial work carried out by Mr. Oosterveld indicates an overall grade of 20
carats per hundred tonnes for the four samples combined. Furthermore, analysis
of the individual samples indicates an increase in grade with depth, with sample
MK1/4, although small, indicating a potential grade of 119 carats per hundred
tonnes for the interval sampled. It should be noted that these are preliminary
estimates, as between 200-400 microdiamonds are typically required to provide
grade estimates with the necessary levels of confidence. The data does indicate,
however, that MK1 has the potential to have a significantly higher grade than
was previously estimated based on the shallow drilling and limited evaluation
work carried out in the 1980's, and is very encouraging.


Mr. Oosterveld concluded that 'the indications are that MK1 might have
significant macro diamond content' and recommended that more work be carried out
to recover additional diamonds in order to allow more accurate estimates of
grade to be made. The Company is also encouraged by the recovery of 3
macrodiamonds (diamonds larger than 0.5 mm) from the samples. Although these
diamonds have not been used for the above grade estimates, they do provide a
further indication of the potential for MK1 to be significantly mineralized.


Tonnage estimate

Mineral Services (Pty) Limited of Cape Town, one of the industry's leading
diamond exploration and evaluation consultancies, has completed preliminary
volumetric modelling based on data from high resolution geophysics and drilling.
Based on this modelling it is estimated that MK1 contains approximately 1.1
billion tonnes of kimberlite to a depth of 1,000 metres.


Further evaluation work planned

The company now plans to recover additional microdiamonds from core drilling and
macrodiamonds from bulk sampling in order to increase confidence in the grade
estimates.


Two additional core holes were drilled into the south-east and north-west lobes
of MK1, to depths of 524 metres and 490 metres, respectively, in January 2008.
Logging of these holes has recently been completed and indicates that the holes
intersected similar volcaniclastic units below the crater sediments to those
intersected in the first hole, and at depths ranging from 200 metres below
surface. Core samples from the approximately 450 metres of volcaniclastic
kimberlite intersected in these holes have been sent to SGS Minerals Services in
South Africa for microdiamond recovery, and results are expected during Q2 2008.


Large Diameter Drill ('LDD') bulk sampling will be undertaken on MK1 during Q2
2008 to recover macrodiamonds, with four separate 100 tonne mini bulk samples
planned. The samples will be treated at the Company's recently commissioned bulk
sampling plant at Tsabong.


Notes:


1. Microdiamond recoveries were carried out by the caustic dissolution
method by SGS Minerals Services, which is accredited to the ISO/IEC 17025
standard for this process. A breakdown of microdiamonds recovered by sieve size
is provided below:

Sieve +1.18 +0.85 +0.60 +0.425 +0.30 +0.212 +0.15 +0.105 +0.075
size
(mm)


Number 2 1 0 3 7 16 17 37 34
of
stones


2. Tinus Oosterveld has more than 45 years of experience in diamond mining
and exploration. He was employed by Anglo American Corporation and De Beers
Consolidated Mines Ltd. for more than 30 years, during which time he was in
charge of De Beers' Mineral Resource Department and responsible for the
assessment of kimberlite deposits throughout the world. He is regarded as one of
the leading authorities in diamond resource evaluation and diamond
geostatistics.


3. The information in this statement has been reviewed by Mr. Tim Wilkes,
B Sc, Pr Sci Nat, who is a qualified person for the purposes of the AIM Guidance
Note for Mining, Oil and Gas Companies. Mr. Wilkes is Chief Operating Officer of
Firestone Diamonds plc and has over 26 years experience in diamond exploration,
mineral resource management and mining. Mr. Wilkes is a member of the
sub-committee for diamonds of the South African Mineral Resource Committee
(SAMREC).


For further information:

Visit the Company's web site at www.firestonediamonds.com, or contact:


Philip Kenny, Firestone Diamonds +44 20 8834 1028/+44 7831 324 645

Leesa Peters/Arabella Hobbs, Conduit PR +44 20 7429 6600/+44 7812 159 885

Mike Jones/Ryan Gaffney, Canaccord Adams (Joint Broker) +44 20 7050 6500

Jamie Cumming, Brewin Dolphin (Joint Broker) +44 141 314 8103/+44 7768 044 620

Ken Fleming, Brewin Dolphin (Nominated Adviser) +44 141 221 7733/+44 7971 835070


Background information on Tsabong:

The Tsabong kimberlite field is located in south western Botswana, approximately
280 km south west of the Jwaneng Mine, which is the world's biggest diamond
mine. Tsabong is one of the largest diamondiferous kimberlite fields in the
world, containing 83 known kimberlites, of which 18 have been proven to be
diamondiferous. Tsabong is noted for the exceptionally large size of many of its
kimberlites, in particular the 180 hectare MK1 kimberlite, which is one of the
largest known diamondiferous kimberlites. The Tsabong field also contains 5
kimberlites larger than 50 hectares and 32 kimberlites between 20 and 50
hectares in size. Access to the area is via tarred road from Gaborone and
infrastructure in the area is good.


Background information on Firestone Diamonds:

AIM quoted Firestone Diamonds plc ('FDI.L') is an international diamond mining
and exploration company with operations in Botswana and South Africa. Botswana
is the world's largest and lowest cost producer of diamonds, with annual
production worth over $2.5 billion, and is considered to be one of the most
prospective countries in the world to explore for diamonds.


Firestone is the largest holder of mineral rights in Botswana's diamondiferous
kimberlite fields, controlling over 21,000 square kilometres around the major
Orapa and Jwaneng mines and the entire Tsabong kimberlite field. Firestone has
92 kimberlites in its portfolio, of which 23 have been proven to be
diamondiferous and 15 are currently being advanced to bulk sampling. Firestone's
mining operations in South Africa include a toll treatment operation in joint
venture with De Beers at the Bonte Koe Mine.


This information is provided by RNS
The company news service from the London Stock Exchange

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