October 25, 2011
Peregrine Diamonds Ltd. (“Peregrine” or “the Company”) is pleased to
report that a 32.54 tonne mini-bulk sample of surface material collected
from the CH-28 kimberlite returned 8.94 carats of commercial-sized
diamonds larger than the 0.85 mm sieve size, for a diamond grade of 0.27
carats per tonne (“cpt”).
The CH-28 kimberlite has an estimated surface expression of two hectares
and is located on the 9,800 square kilometre Chidliak project
(“Chidliak”), Baffin Island, Nunavut, Canada. CH-28 is approximately 50
kilometres north of the Southern Focus Area, an area at Chidliak with an
eight kilometre radius that currently hosts six kimberlites with
The mini-bulk sample from the CH-28 kimberlite was processed by dense
media separation (“DMS”) at the Saskatchewan Research Council
Geoanalytical Laboratories (“the SRC”). The diamond results are
presented in square mesh sieve format in the following table.
SUMMARY OF CH-28 MINI-BULK SAMPLE DIAMOND RESULTS
The diamond content of the CH-28 sample as determined by DMS
processing may not be representative of the overall diamond content of
the CH-28 kimberlite due to a number of factors including the limited
surface area of the kimberlite from which the CH-28 sample was collected
and the relatively small size of the sample.
|Dry Sample Weight (tonnes)
||Numbers of Diamonds According to Sieve Size Fraction (mm)
|Diamond Content (cpt) (+0.85 mm)
The four largest diamonds were described by the SRC as a 0.98 carat
brown tetrahexahedroid, a 0.44 carat white/colourless distorted crystal,
a 0.37 carat off-white cubic diamond and a 0.37 carat white/colourless
tetrahexahedroid. The remaining nine diamonds in the +2.36 mm sieve
size range in weight from 0.15 to 0.35 carats, with one being
white/colourless, another grey and the remaining seven off-white.
Images from CH-28 are available at the following link here
SAMPLE COLLECTION, PROCESSING AND DIAMOND RECOVERY
The 32.54 tonne CH-28 sample was collected from in-situ surface material
(subcrop) over an area measuring approximately 50 by 50 metres. The
sample consisted of macrocrystic kimberlite with abundant indicator
minerals. The sample collection and shipment process was conducted
under strict chain of custody protocols and was supervised by senior
At the SRC, the sample was crushed by a jaw crusher with a gap set at
approximately 30 mm. The sample was then fed into a five tonne per hour
DMS plant where it was subjected to scrubbing and two stages of
crushing. DMS concentration was performed on +0.85-12.0 mm feed
material. Heavy mineral concentrate from the DMS was treated through a
two-stage Flow Sort x-ray sorter and vibrating grease table recovery
circuit. The resulting concentrates were then hand-sorted for final
diamond recovery using sealed glove boxes.
As an element of Peregrine’s Quality Assurance/Quality Control
protocols, 179 numerically laser-etched natural diamond tracers ranging
in size from 0.15 to 2.84 carats were added to the sample bags in the
field and at the SRC, and 177, or 99 percent, of the tracers were
recovered from the DMS concentrate.
The discovery of the CH-28 kimberlite was first reported on September
23, 2010. A 238.9 kilogram surface sample yielded 174 diamonds larger
than the 0.106 mm sieve size, including five diamonds larger than the
0.850 mm sieve size which weigh a total of 0.196 carats. As reported on
June 2, 2011, a core hole was drilled across CH-28 and a 393.1 kilogram
sample of drill core yielded 251 diamonds larger than the 0.106 mm
sieve size including 0.13 carats of commercial-size (+0.85 mm) stones.
The SRC is an independent laboratory that is accredited by the Standards
Council of Canada to the ISO/IEC Guide 25 standard for diamond recovery
by caustic fusion.
Mr. Peter Holmes, P.