Stornoway Reports 2,681 Carats Recovered from Renard 3 Including a 10.15 Carat Stone


Stornoway Diamond Corporation (TSX-SWY) is pleased to provide complete diamond recovery results from the Renard 3 kimberlite, the first individual kimberlite bulk sample to be completed as part of the Renard bulk sample program in north-central Québec. Stornoway, and 50:50 joint venture partner SOQUEM INC. ("SOQUEM"), are currently engaged in a program of sampling at Renard designed to recover a minimum 6,000 carats of diamonds from three separate kimberlite pipes. Renard 3 has now returned a total of 2,681 carats of diamonds from 12 separate sub-samples with a combined dry sample weight of 1,929 tonnes, representing an overall diamond recovery of 139 carats per hundred tonnes (cpht) for stones retained on a +1 Diamond Trading Company (DTC) screen. Diamond recovery from individual sub-samples varied between 78 cpht and 223 cpht, with the largest diamond weighing 10.15 carats. Complete Renard 3 diamond data, after utilizing both x-ray sorter and grease table recovery circuits, are as follows:

Sub-Sample Dry Weight
(retained on +1 DTC screen)
(retained on a +1 DTC screen)
Diamond Content 1
Largest Diamond
R3-3002 3 59.7 686 74.10 124 4.13
R3-3006 3 122.0 2262 220.45 181 2.50
R3-3008 3 235.5 3212 351.72 149 7.78
R3-3012 222.4 3268 316.95 143 3.62
R3-3014 169.1 2132 236.68 140 3.62
R3-3016 176.2 1392 187.20 106 6.36
R3-3018 149.2 1079 136.24 91 4.26
R3-3020 168.4 1118 142.39 85 2.43 4
R3-3102 155.4 2389 248.26 160 3.12
R3-3104 163.1 1315 127.21 78 2.28
R3-3107 164.2 3847 365.68 223 10.15
R3-3109 143.4 2982 274.52 191 2.28
Total 1928.6 25682 2681.40 139  
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 the location/size of the underground samples and processing parameters
2Carats per hundred tonnes
3Preliminary results for sub-samples R3-3002, 3006 and 3008 were previously disclosed in a Stornoway Press Release dated May 17, 2007
4 3.16 carats if a two piece broken stone (2.12ct and 1.04 ct) is reassembled

CEO Eira Thomas stated, "The final diamond recovery results from Renard 3 have exceeded our expectations. Overall diamond content, the frequency of large stones and indicative diamond qualities from Renard 3 all equal or exceed the observed results from earlier sampling campaigns. It is particularly noteworthy that this sample has yielded a higher average diamond content of 139 cpht compared to 126 cpht from historical work, despite lower recoveries of smaller stones attributable to plant design. We continue to be encouraged by the potential of the Renard Project to become Quebec's first diamond mine."

The five largest diamonds recovered from Renard 3 are a 10.15 carat light off-colour gem octahedron, a 7.78 carat near-gem clivage, a 6.36 carat colourless gem octahedron, a 6.09 carat colourless gem octahedron, and a 5.00 carat colourless macle (a photograph of these diamonds can be found on the Stornoway website at Three of these diamonds were previously reported in a May 17th press release. The increase in diamond content on the previously reported samples (R3-3002, 3006, and 3008) is a result of additional diamond recovery from the grease table finish applied to all x-ray sorter rejects.

To date, some 5,400 dry tonnes of kimberlite has been processed at the 10 tonne per hour Dense Media Separation (DMS) plant located at the Renard Project site. This comprises 1,929 dry tonnes of Renard 3, approximately 2,238 dry tonnes of Renard 2 and approximately 1,230 tonnes of Renard 4. Stornoway anticipates that a minimum 6,000 dry tonnes of kimberlite will have been processed through the DMS plant by the end of June, at which time on-site processing will have been completed. Final diamond recovery at Stornoway's wholly owned laboratory located in North Vancouver is expected to be completed within the third quarter with a full market valuation following thereafter. Diamond recovery results for the Renard 2 and Renard 4 kimberlites will be released on a batched basis as they become available.

Comparative Historical Data

Between 2004 and 2005, Stornoway's wholly owned subsidiary Ashton Mining of Canada Inc. ("Ashton") and its JV partner SOQUEM collected a 146 tonne mini-bulk sample from Renard 3 by reverse circulation drilling that yielded a recovered diamond content of 126 cpht (Ashton press release of January 26, 2005). The largest diamond recovered during that program was a colourless 4.30 carat octahedron.

Historical diamond recovery results now reported from Renard 3 are as follows:

Disclosure Date Dry Weight (tonnes) Carats Diamond Content3
Largest Diamonds
June 20, 20071 1938.0 2681.40 5 139 10.15, 7.78, 6.36
January 26, 20052 146.0 184.00 6 126 4.30, 2.70, 2.29
December 13, 20042 8.6 5.89 6 68 0.88
June 9, 20042 5.1 7.81 6 153 1.82, 1.01
December 18, 20022 4.9 6.54 7 134 0.73
1 Total includes preliminary diamond recovery results reported by Stornoway on May 17th, 2007
2 Reported by Ashton Mining of Canada Inc.
3 The 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 the location and size of the samples or drill holes
4 Carats per hundred tonnes
5 Represents only stones retained on a +1 or greater DTC screen, as discussed below
6 Represents only stones retained on a +1.18 mm square mesh screen
7 Represents only stones retained on a +0.85 mm square mesh screen

Renard 3 Geology

The twelve individual samples from Renard 3 reported above were collected by underground decline 55m below surface at the 455m level. Underground mapping has outlined six geological units, comprised of four fragmental kimberlite breccias (typical tuffisitic kimberlite breccia to tuffisitic transitional kimberlite breccia), a hypabyssal kimberlite breccia, and a hypabyssal kimberlite with coarse olivine. Variations in diamond content are apparent between these geological units, with the slightly elevated diamond contents corresponding to the hypabyssal kimberlite with coarse olivine (223 cpht in sample 3107) and the hypabyssal kimberlite breccia (191 cpht in sample 3109). Diamond content of the fragmental breccias varies from 78 cpht to 181 cpht, with a weighted average of 125 cpht.

Recovered diamond content from individual sub-samples, and the complete Renard 3 underground sample, does not conform to the definition of a "mineral resource" grade established by National Instrument ("NI") 43-101. The Renard 3 samples processed to date have been selected from each of the geological units encountered in the underground drifts. Stornoway is in the process of establishing detailed geological models for each of the Renard kimberlites to be utilized in a subsequent NI 43-101 compliant resource calculation. As a component of this work, individual geologic units observable within the pipes will be reconciled with diamond recovery information.

Scientific and Technical Data

Diamond results reported in this release are based on sample processing by a 10 tph DMS plant owned by Stornoway (through Ashton) and SOQUEM in joint venture, and operated by Stornoway, and on the recovery of diamonds from concentrate at Stornoway's wholly owned and operated mineralogical laboratory in North Vancouver, British Columbia. Quality assurance protocols and actual operating procedures for the processing, transport and recovery of diamonds under the Renard bulk sample program, including arms-length security provisions, conform to industry standard Chain of Custody provisions and are subject to the review of AMEC Americas Ltd. who have been contracted to provide third party accreditation for program data.

For the Renard bulk sample program, individual kimberlite samples are prepared through a primary jaw crusher prior to introduction to the 10 tph DMS. To facilitate production of a heavy mineral concentrate, -20mm material is fed directly into the DMS and +20mm material is reduced through a secondary cone crusher set at 10mm. DMS coarse reject "floats" are re-crushed to -6mm and re-circulated through the DMS. During the processing of the first seven Renard 3 sub-samples (3002, 3006, 3008, 3012, 3102, 3104 and 3107), a 1.2mm by 13.0mm slotted screen was employed. The subsequent five samples were processed utilizing a 1.0mm by 12.0mm slotted screen. Use of the 1.0mm by 12.0mm slotted screen would slightly increase recovery of smaller diamonds, but the minimum stone size would still be greater than that retained on a +1 DTC screen. Following delivery to North Vancouver, the resultant DMS concentrate was then 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. All 12 sub-samples from Renard 3, as reported above, include diamonds recovered from (a) two x-ray sorter passes and (b) the grease table recovery circuit. Diamond recovery reported above pertains only to stones retained on a +1 DTC screen, approximately equivalent to a 0.85mm square mesh screen. However, the bottom cut-off screen sizes used on the DMS will result in under-recovery of smaller diamonds and will not allow a direct comparison with previously reported diamond contents. 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. The Renard bulk sample program is managed by Dave Skelton, P.Geol., Senior Project Manager. Stornoway's diamond exploration programs are conducted under the direction of Robin Hopkins P.Geol, Vice President, Exploration, a Qualified Person under NI 43-101.

Interest Payment Shares Issued

Stornoway has made the first quarterly interest payment due on the $20,000,000 unsecured Series A and Series B convertible debentures (see Stornoway Press Release dated March 16, 2007) by issuing a total of 604,900 common shares at a value of $0.9919 per share to the holders of the debentures. The price per common share is based on 95% of the volume weighted average trading price of the shares, three days prior to the June 15th payment date. The debentures bear interest at 12% per annum, payable quarterly in cash or in shares, at Stornoway's election. The shares are subject to a hold period that will expire July 17, 2007.

Stornoway Diamond Corporation

Stornoway Diamond Corporation is one of Canada's leading diamond exploration and development companies, involved in the discovery of over 150 kimberlites in six 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.


SOQUEM is a wholly-owned subsidiary of Société générale de financement du Québec ("SGF"). The SGF, the Quebec industrial and financial holding company, has as its mission to undertake economic development projects in the industrial sector in cooperation with partners and in compliance with the economic development policies of the Government of Quebec.

On behalf of the Board

/s/ "Eira Thomas"
Eira Thomas
Chief Executive Officer

For further information, please contact Nick Thomas at 604-331-2259 or (888) 338-2200
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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 the Company's expectations are in Company documents filed from time to time with the Toronto Stock Exchange and provincial securities regulators, most of which are available at . The Company disclaims any intention or obligation to revise or update such statements.