Stornoway Reports Initial Diamond Results From Aviat 200 Tonne Bulk Sample: 210 Cpht In First 43 Tonnes
February 19, 2009
Stornoway Diamond Corporation (TSX-SWY) and Hunter Exploration Group (Hunter) are pleased to report results from the processing of the first 43 tonnes of an approximately 200 tonne sample of kimberlite collected during 2008 from within the Eastern Sheet Complex ("ESC") of the Aviat Project, Nunavut. To date, 89.55 carats of diamonds have been recovered from 42.67 tonnes (dry weight) of kimberlite, representing an overall diamond recovery of 210 carats per hundred tonnes (cpht) for stones retained on a +1 DTC screen. The largest diamond recovered in this sample is a 0.81 carat grey fragment. The largest diamond recovered from the ESC from previous sampling is a 3.64 carat gem quality white dodecahedron (see press release dated January 21, 2008).
This first 43 tonnes of sample was collected at a kimberlite outcrop within the ESC previously named "AV6". The balance of the 200 tonne sample was collected at a nearby outcrop previously named "AV2". The two outcrop samples are being processed separately, but "AV6" and "AV2" are now considered to represent two exposures of the same "ES1" kimberlite sheet occurring within the ESC. The second tranche of diamond recovery results are expected before the end of the first quarter.
Complete diamond recovery data, following Dense Media Separation ("DMS") processing and utilizing both x-ray sorter and grease table recovery circuits, are as follows:
|Sample||Dry Weight (tonnes)||Stones (retained on +1 DTC screen)||Carats (retained on +1 DTC screen)||Diamond Content1 (cpht)2||Largest Diamonds (carats)|
|ES1 Part 1 ("AV6"-2008)||42.67||24473||89.5453||210||0.81, 0.77, 0.67|
1The estimated diamond content, expressed as carats per hundred tonnes, may not be representative of the overall diamond content of the body due to a number of factors, including location/size of the samples and processing parameters.
2Carats per hundred tonnes
3Represents only stones retained on a +1 or greater DTC screen, as discussed below
Matt Manson, President and CEO, stated: "We are encouraged by these first results from the 2008 sampling program at Aviat, which have confirmed very high diamond grades within the dominant kimberlite body of the Eastern Sheet Complex. This is consistent with the recently reported conceptual study of the project, authored independently by SRK Consulting (Canada) Inc. and released in October 2008. Processing of the balance of the 200 tonne sample is currently underway."
The Aviat Project is located on the Melville Peninsula in eastern Nunavut, Canada, and is a joint venture between Stornoway (90%) and Hunter (10%). Stornoway holds 100% of the diamond marketing rights. A map outlining the series of significantly diamondiferous kimberlite pipes and sheets discovered to date is available at http://www.stornowaydiamonds.com/Kimberlite-Bodies-October-6.jpg.
Recently, Stornoway released the results of a conceptual study at Aviat authored by SRK Consulting (Canada) Inc. ("SRK") an independent, international consulting practice (Stornoway press release of October 7, 2008). This study concluded that based on the drilling undertaken to date, the ESC contained an estimated 12.4 to 16.0 million tonnes of kimberlite material within four separately distinguishable kimberlite sheets of the ESC. One of these sheets, named ES1, spans an area of some 260 hectares and represents about 78% of the total kimberlite volume. Based on the limited micro and macro diamond data collected during the 2003 to 2007 field campaigns, SRK estimated a total diamond content of 235 carats per hundred tonnes (cpht) +/- 30 cpht at a bottom cut-off of +1.0mm (approximately equivalent to a +2 DTC sieve). The conceptual range of total content of kimberlite material and the estimate of total diamond content, taken together, imply between 24.1 to 40.3 million carats in the ground, after an allowance for approximately 5% internal dilution within the conceptual model. This conceptual study did not include Aviat's pipe-like kimberlite bodies (AV1, AV4 and AV9), kimberlite sheets outside of the currently defined ESC (such as AV1W and AV5) or drill intersections of as yet un-named kimberlite sheets that have not yet been integrated into the overall geologic model. The ESC remains open down dip to the southeast, and across the Centennial Fault to the west.
The potential quantity of diamonds that can be inferred from the above estimates is conceptual in nature and does not constitute a mineral resource. The reader is cautioned that to date there has been insufficient exploration to define a mineral resource according to CIM Definition Standards for Mineral Resources and Mineral Reserves for the ESC, and it is at this stage uncertain if further exploration will be able to delineate a mineral resource for the ESC.
Following receipt of the final diamond recovery results from the balance of the 200 tonne sample, Stornoway expects to conduct a market valuation exercise on the full parcel of diamonds recovered from the ES1 kimberlite sheet to date. This will be undertaken once the world rough diamond market, which is currently experiencing internal financial volatility, has stabilized such that valuation data usable for advanced level exploration planning can be obtained. Although this valuation work, being based on a small parcel of diamonds, will provide only a preliminary sense of the average diamond price at Aviat, it will be sufficient, in conjunction with the October 2008 conceptual study, to provide a qualified estimate of value contained within the ESC. This estimate will in turn support subsequent desktop studies aimed at determining optimum mining scenarios for the ESC. The conclusions of these studies will dictate the nature and type of future sampling required to obtain a National Instrument ("NI") 43-101 compliant mineral resource statement at Aviat.
Note on Diamond Recoveries
The estimate of total diamond content for the ESC sheets provided in the SRK independent study (235 +/- 30 cpht undiluted) used a 1.0mm (approximately equivalent to a +2 DTC sieve) bottom cut-off and assumed 100% recovery of stones of all size fractions. No corrections were applied for breakage and/or loss of smaller diamonds that would typically occur during recovery of diamonds in a commercial DMS plant. Quantification of commercial diamond recoveries is extremely difficult at this stage of the project due to numerous factors that need to be studied in greater detail (for example: economical bottom cut-off; efficiencies of the process plant; diamond breakage and/or loss; etc.). However, SRK has stated that in a commercial DMS plant it is not unreasonable to expect a 15-20% reduction in recovered diamonds from the total diamond content estimation assuming a similar bottom cut-off of +1.00 mm.
The initial results from the ES1 kimberlite sheet reported today represent diamonds retained on a +1 DTC screen (approximately equivalent to a 0.85mm square mesh screen) and, as described below, the sample was processed utilizing a crushing regime designed to maximise the recovery of small diamonds in exploration scale samples. The efficiency of small stone recovery achieved with this method is higher than would be expected in a commercial DMS plant. The sample results, therefore, better approximate a total diamond content measurement of the ES1 kimberlite sheet, and as such are consistent with the estimated range of total diamond content provided in the SRK independent study. As with the total diamond content estimate, actual diamond recoveries in a commercial setting can be expected to be reduced with respect to diamond content and substantially higher with respect to average stone size as a large number of very small diamonds are not recovered.
Previously reported DMS results from kimberlite outcrops now considered part of the ES1 kimberlite sheet are provided in the table below. The increase in diamond content evident in the larger samples is ascribed to the increase in sample size, and the collection of fresher, more representative kimberlite.
|Disclosure Date||Sample Type||Dry Weight (tonnes)||Carats||Diamond
|February 19, 2009||Outcrop ES1 Part 1 ("AV6"-2008)||42.67||89.55||2103||0.81, 0.77, 0.67|
|January 21, 2008||Outcrop "AV2" (2007)||20.60||33.36||1624||3.64, 0.551, 0.525|
|January 11, 2007||Outcrop "AV2" (2005)||2.19||1.58||724||0.19|
|July 11, 2006||Outcrop "AV7" (2005)||2.32||1.78||774||0.19|
|June 21, 2006||Outcrop "AV6" (2005)||2.15||2.08||974||0.10|
1The estimated diamond content, expressed as carats per hundred tonnes, may not be representative of the overall diamond content of the body due to a number of factors, including location and size of the samples or drill holes
2Carats per hundred tonnes
3Represents only stones retained on a +1 or greater DTC screen
4Represents only stones retained on a +0.85 mm square mesh screen
Scientific and Technical Data
Diamond results reported in this release are based on DMS processing work completed by Microlithics Laboratories, Thunder Bay, Ontario, an independent mineral process laboratory currently providing services to Stornoway. The 42.67 tonne sample was processed through a 1.5 tonne per hour (tph) DMS plant designed to recover stones retained on a 0.85mm square mesh sieve. Kimberlite was prepared through a primary jaw crusher, with -10 mm material fed directly into the DMS. All +10 mm material was subsequently reduced through secondary cone crushing. A further re-crush of +2mm reject material is performed to facilitate the recovery of small diamonds. Recovery of diamonds from the DMS concentrate was carried out at Stornoway's wholly owned diamond laboratory in North Vancouver whereby concentrates were processed twice through x-ray sorter equipment to generate a final concentrate which was hand sorted to extract diamonds. A grease table finish was used to recover diamonds from all x-ray sorter rejects. Quality assurance protocols, security and actual operating procedures for the processing, transport and recovery of diamonds conform to industry standard Chain of Custody provisions. As part of Stornoway's ongoing QA/QC program, DMS tails, concentrate residues and other materials are also subject to audit. Any significant changes to the recovered diamond grades provided above will be reported when available.
Stornoway Diamond Corporation
Stornoway Diamond Corporation is one of Canada's leading diamond exploration and development companies, involved in the discovery of over 200 kimberlites in seven Canadian diamond districts. The Company benefits from a diversified diamond property portfolio, a strong financial platform and management and technical teams with experience in each segment of the diamond "pipeline" from exploration to marketing. Stornoway's diamond exploration programs are conducted under the direction of Robin Hopkins, P.Geol. (NT/NU), Vice President, Exploration, a Qualified Person under NI 43-101. Mr Hopkins has read this press release and approves of its contents.
On behalf of the Board
STORNOWAY DIAMOND CORPORATION
/s/ "Matt Manson"
President and Chief Executive Officer
For further information, please contact Nick Thomas , Investor Relations Manager at 604.983.7754 or 1.877.331.2232