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Shear
Diamonds Ltd. (TSX VENTURE:SRM
- News) today announced
the confirmation of a sample grade of 11.3 carats per tonne
("cpt") from an internal audit of 308.8
kg of kimberlite concentrate from the recovery
reject tailings at the Jericho Diamond Mine. A total of 52 macro diamonds
representing 3.5 carats were recovered from a small sample collected across
surface of the recovery rejects stockpile at the mine site, resulting in the
sample grade of 11.3 cpt with the largest stone
being a 0.54 carat diamond. during operations.
"These
audit results allow us to begin to determine a better methodology for future
processing of Jericho's kimberlite in order to
achieve optimum diamond liberation and recovery," says Shear President
Pamela Strand. "Also, we believe that based on these high diamond
contents, that Jericho's recoverable diamond grade has the potential to
increase substantially."
The
results of the Shear audit is summarized in the
following table.
Shear
Recovery Rejects Audit:
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Weight
of
Weight of
Diamonds Number
of
Jericho Kimberlite
Tails Recovered total stones
Complex
Audited (kg)
(carats)
+0.85
(+0.85mm)
mm
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Recovery Rejects -
SRC
308.8
3.50
52
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0.85 1.18 1.70 2.36 3.35 4.75 Sample
Jericho Kimberlite
mm
mm mm mm mm mm Grade
Complex
Sieve Sieve Sieve Sieve Sieve Sieve
cpt
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Recovery Rejects -
SRC
5
24
21
1
1
0 11.3
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For
the purposes of the 2010-2011 audit, the sample,
processed at the Saskatchewan Research Council's Geoanalytical
Laboratories Diamond Services ("SRC"), was fed into an High
Pressure Grinding Roll ("HPGR") and crushed with a 4mm gap setting.
The crushed concentrate was then run through a diamond recovery circuit
consisting of an X-Ray Flowsort and Grease Table
audit using a bottom cutoff size of 0.85mm. By reprocessing a small sample of
recovery reject tailings through an HPGR crush and recovery circuit, Shear
was aiming to establish the presence of possible locked diamonds (those that
were not liberated by the original crushing circuit and remain trapped in kimberlite).
The
purpose of Shear's mini-audit was to confirm the results of a 4,048.5 kg
sample from the recovery reject stockpile collected by Tahera
Diamond Corporation ("TDC") in late 2007, which yielded 1,345
stones weighing 58.8 carats for a sample grade of 14.5 cpt.
The largest recovered stone weighed 0.94 carats. This sample was treated at
SGS Lakefield Research Limited ("SGS") using a similar recovery
circuit with a re-crush down to 4mm, and a 2-pass X-Ray Sortex
and 2-pass grease table audit. Screened material +1mm to -4mm was run through
a magnetic separator and diamonds from the non-magnetic material were
recovered by caustic fusion due to the large volumes of concentrates.
TDC
had also submitted a 1,345 kg sample of coarse processed kimberlite
("CPK") tails to SGS for audit purposes in 2007. The sample was run
through a Dense Media Separation ("DMS") circuit with an HPGR
re-crush at a 4mm gap setting, and a bottom screen size of 0.85mm. The sized
concentrate underwent HIMS (magnetic separation) processing and the
non-magnetic fractions were then hand sorted for diamonds. A total of 45
stones weighing 1.14 carats were recovered for a sample grade of 0.84 cpt. The largest recovered stone weighed 0.22 carats.
TDC
conducted a much larger on-site audit of the CPK (approximately 11,000 tonnes) which was suggestive of similar results as
outlined below. Estimates from the historic mine records of process plant
by-products for the recovery rejects and CPK are 25,000 tonnes
and 900,000 tonnes respectively. A portion of the
CPK was used for construction purposes and is no longer accessible for
re-processing and recovery of diamonds.
The
results of the past audits are summarized in the following table.
Results
of Past Recovery Reject and CPK Tailings Audits:
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Weight of
Weight
of Diamonds Number of
Jericho Kimberlite
Tails Recovered total stones
Complex
Audited (kg)
(carats)
+0.85
(+0.85mm)
mm
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Recovery Rejects -
SGS (2007)
4,048.5 58.77
1,345
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CPK Tails - SGS
(2007)
1,345.5
1.14
45
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0.85 1.18 1.70 2.36 3.35 4.75 Sample
Jericho Kimberlite
mm
mm mm mm mm mm Grade
Complex
Sieve Sieve Sieve Sieve Sieve Sieve
cpt
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Recovery Rejects -
SGS (2007)
271 861 182 25 6 0 14.5
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CPK Tails - SGS
(2007)
30
12
3
0
0
0 0.8
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About
Shear Diamonds Ltd.
Shear
is a Canadian-based company focused on diamond exploration and development in
Canada's North, where it explores established diamond districts and has
discovered new ones. Shear currently has a portfolio of eight diamond
projects, including three advanced projects with development potential. Shear
holds a 100% interest in its recently acquired Jericho Diamond Mine and
surrounding exploration assets, located in the Kitikmeot region of Nunavut.
Jericho is Nunavut's first and only diamond mine.
Pamela
Strand, P. Geol., Shear's President and Chief Executive Officer, and Jennifer
Burgess, P. Geo. Shear's VP Exploration, are qualified persons for purposes
of National Instrument 43-101 who supervised the preparation of the
information forming the basis for this press release.
On
behalf of the Board of SHEAR DIAMONDS LTD.
Pamela
Strand, P. Geol., President & CEO
Julie
Lassonde, Executive Chairman
This
news release may contain forward looking statements, being statements which
are not historical facts, including, without limitation, statements regarding
potential mineralization, exploration results, resource or reserve estimates,
anticipated production or results, sales, revenues, costs,
"best-efforts" financings or discussions of future plans and
objectives. There can be no assurance that such statements will prove
accurate. Such statements are necessarily based upon a number of estimates
and assumptions that are subject to numerous risks and uncertainties that
could cause actual results and future events to differ materially from those
anticipated or projected. Important factors that could cause actual results
to differ materially from Shear's expectations are in its documents filed
from time to time with the TSX or the TSX Venture Exchange and provincial
securities regulators, most of which are available at www.sedar.com.
Shear disclaims any intention or obligation to revise or update such
statements.
The
TSX Venture Exchange has not reviewed and does not accept responsibility for
the adequacy or accuracy of this release.
Contact:
Pamela Strand, P.
Geol.
Shear Minerals Ltd.
President and CEO
(780) 435-0045 or 1-866-298-9695
www.shearminerals.com
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