Encouraging
Diamond Grades From Tongo Kimberlite Project In Sierra Leone
NOT FOR
DISTRIBUTION IN THE UNITED STATES OR FOR DISSEMINATION TO US NEWS WIRE
SERVICES.
Stellar Diamonds plc ("Stellar" or the "Company")
Stellar Diamonds plc, the London listed (AIM:STEL) diamond mining and exploration
company focused on West Africa, is pleased to report encouraging initial
diamond grades from bulk sampling at the Company's 100% owned Tongo kimberlite project in
eastern Sierra Leone.
Highlights:
- Initial sample of 69 tons
returned in-situ grade of 130cpht for Tongo Dyke
1
- 90% of diamonds have been
classified as gem quality
- Eight diamonds greater than 1
carat recovered
- Previous diamond parcel from Tongo Dyke 1 re-valued at $169 per carat
- 5 ton per hour Dense Media
Separation ('DMS') plant fully commissioned and operating
Karl Smithson, Chief Executive
Officer, commented:
"The initial processing results from the Tongo kimberlite bulk sampling programme
are highly encouraging, with an in-situ kimberlite
grade of 130 carats per hundred tons ("cpht")
being recovered from the first 69 tons processed during the commissioning of
the DMS plant. Taking into account dilution incorporated during the sampling
process, the diluted grade is calculated at 86cpht. The predominance of gem
quality stones in the diamond population so far observed can only bode well for
the future diamond value of this kimberlite body.
"We are accelerating the processing rate in order that a representative
parcel of diamonds can be exported to Antwerp for valuation purposes. The
objective is to collect a 1,000 carat to 2,000 carat bulk sample, the results
of which will determine the next phase of evaluation and development work.
"Stellar's strategy is to grow significantly by
developing a series of high-grade kimberlites into
economic diamond mines. In the past six months Stellar has delivered excellent
drilling and microdiamond results from the Droujba kimberlite pipe in Guinea and now we are able to announce
initial high-grades from the Tongo kimberlite dyke. We will continue the development of these
key assets over the coming months."
Tongo Bulk Sampling
A total of 1,000 tons of sample has been collected to date from a 70m long
section of the 2.5km long kimberlite Dyke 1. The
sample is being extracted by drilling and blasting at a depth of 5m to 10m
below surface. The kimberlite averages 70cm in width
and the sample trench averages 1.04m in width with the fresh granite that
comprise the wall rock proving to be hard and stable in nature.
The first 1,000 tons have been batched into 5 samples to date. The first sample
currently being processed weighs approximately 303 tons and is comprised of 201
tons of kimberlite and 102 tons of country rock
incorporated during the drilling and blasting of the bulk sample, giving an
effective dilution of 34% to the in-situ kimberlite.
Tongo Processing Plant
Construction and commissioning of the Tongo
processing plant has now been completed. The plant has a bottom cut-off size of
1mm and is comprised of a small scrubber, a primary jaw and secondary cone crusher
and a 5 ton per hour DMS cyclone. Diamond recovery is undertaken over grease
tables in a security controlled container.
Now that plant commissioning has been completed the rate of processing is
expected to increase going forward.
Tongo Bulk Sampling Results
The first 68.95 dry tons of kimberlite
processed during commissioning of the plant yielded 59.25 carats of +1mm stones
at a diluted grade of 85.93cpht. This result represents a diluted sample grade
as an estimated 34% of the sample comprised granitic country rock incorporated
during the blasting and sampling process. The + 1mm in-situ grade of the kimberlite sample is therefore calculated to be
approximately 130cpht.
Kimberlite
|
Diluted Dry Tons
|
Carats
|
Diluted +1mm Grade (cpht)
|
In-Situ
Dry Tons
|
Carats
|
In-Situ +1mm Grade (cpht)
|
Number of Diamonds
|
Average Stone Size (ct.)
|
Tongo
|
|
|
|
|
|
|
|
|
Dyke
1
|
68.95
|
59.25
|
85.93
|
45.51
|
59.25
|
130.19
|
353
|
0.17
|
Note:
In-situ kimberlite tons calculated by subtracting the
granite tons incorporated during the drilling and blasting process
Tongo Dyke 1 Diamond Characteristics
Of the 59.25 carats so far recovered from the bulk sample 53.46 carats (90%)
are classified as being of gem quality, whereas 5.87 carats (10%) are
classified as non-gem. The goods have been further classified as predominantly sawables (53%) and makeables
(41%) with a small clivage (6%) component.
Two stones over 2 carats and six stones of over 1 carat have been recovered
from this small parcel, which suggests a good coarse size distribution to the
diamond population. The largest diamonds contained in the initial parcel weigh
2.64, 2.02, 1.42, 1.41, 1.16, 1.12, 1.10 and 1.06 carats.
While no conclusions can yet be drawn as to the diamond value of the Dyke 1 kimberlite, due to the small parcel of stones obtained so
far, a 130 carat parcel of stones previously recovered from Dyke 1 by Stellar
was recently re-valued for the Company at $169 per carat. The same parcel was
valued at $144 per carat in May 2010, with the relative price increase
reflecting the improvement in the diamond market in the second half of 2010.
The average diamond size from the current 59.25 carats is 0.17 per stone,
almost twice that of the previous 130 carats of 0.09 per stone, which would
possibly suggest a higher diamond value for the
smaller parcel.
About Stellar Diamonds plc
Stellar is a London (AIM: STEL) listed diamond mining and exploration company
that has a portfolio of projects in West Africa.
Stellar also owns full rights over four high-grade kimberlites
that are the focus of exploration and development. In Sierra Leone at the Tongo project a bulk sampling programme
is ongoing on one key kimberlite to assess the diamond
grade and value. At the Kono underground trial mine,
bulk sampling by the Company has produced 4,200 carats as part of an economic
evaluation exercise. In Guinea drilling is continuing on the diamondiferous Droujba kimberlite pipe and bulk
sampling is being planned on the high grade Bouro kimberlite dyke, which is adjacent to the Company's Mandala alluvial diamond mine.
For further information please contact the following or visit the Company's
website at www.stellar-diamonds.com.
In accordance with the AIM Rules, the information in this announcement has been
reviewed by Karl Smithson, CEO of Stellar, a qualified
geologist with 22 years' experience.
Stellar Diamonds plc
Karl Smithson, Chief Executive
Tel: +44 (0) 7783 707971
Angus Ogilvie, Finance Director
Tel: +44 (0) 7885 201 903
RBC Capital Markets
Martin Eales / Daniel Conti
Tel: +44 (0) 20 7653 4000
Northland Capital Partners Limited
Charles Vaughan / Gavin Burnell
Tel: +44 (0) 20 7492 4763
Pelham Bell Pottinger
Charles Vivian / James MacFarlane
Tel: +44 (0) 20 7861 3232