Stornoway Diamond Corporation (TSX:SWY) is pleased to announce the results of a recent diamond valuation exercise undertaken in support of the ongoing feasibility study at the Renard Diamond Project, Stornoway's 100% owned flagship project located in north central Quebec. The diamond valuation was performed under the supervision of WWW International Diamond Consultants Ltd. ("WWW") in Antwerp, Belgium between May 9th-13th, 2011. Highlights are as follows:

--  A base case modeled diamond price estimate of US$182 per carat for the
    diamond samples from the Renard 2 and 3 kimberlite pipes, an increase of
    56% over the previous estimate determined in September 2009.

--  A base case modeled diamond price estimate of US$112 per carat for the
    diamond sample from the Renard 4 kimberlite pipe, an increase of 49%
    over the previous estimate.

--  "High" diamond price models of US$236, US$205 and US$185 per carat for
    the Renard 2, 3 and 4 kimberlite pipes respectively, based on an
    analysis of diamond price and size distribution upside on the individual
    valuation samples.

Matt Manson, President and CEO, commented: "This comprehensive new valuation of the Renard bulk sample diamonds has confirmed the substantial increases in rough diamond prices of the last 18 months, brought about by sustained demand growth and tightening mine supply. The new price data are expected to have a very positive impact on the project's revenue profile and mining margin. Our feasibility study, which is on track for delivery in the third quarter, will outline a project with a high production rate, high diamond price, long mine life potential, and available road and power infrastructure in a leading, pro-mining jurisdiction. This combination of factors makes Renard one of the most compelling undeveloped diamond assets in the world."

Diamond Valuation Results

Table 1: Diamond Valuation Results, Renard Kimberlite Pipes
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                      Achieved Prices for the
                          Valuation Samples          WWW Price Modeling
                    --------------------------------------------------------
                              Average
                      Number  of Inde-               WWW
                          of  pendent      WWW      Base      WWW       WWW
              Valua- Indepen-   Valua-   Valua-     Case    "High" "Minimum"
               tion     dent    tions     tion     Model    Model     Model
Kimberlite   Sample    Valua-    (US$/    (US$/     (US$/    (US$/     (US$/
 Body       (carats)   tions    carat)   carat)    carat)   carat)    carat)
----------------------------------------------------------------------------
Renard 2      1,580        5     $173     $195      $182     $236      $163
Renard 3      2,753        5     $171     $190      $182     $205      $153
Renard 4      2,674        5     $100     $107      $112     $185      $105
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Notes: All Price Estimates Based on a +1 DTC sieve size cut-off

Table 1 summarizes the results of the valuation exercise. In addition to WWW, four other diamond companies also provided price estimates, and the average of the five valuations was used by WWW to construct a diamond price model with "High" and "Minimum" sensitivities.

Diamond price models represent the true diamond price that might reasonably be expected for each kimberlite upon production based on standard commercial-scale recoveries of all diamond size classes. They differ from the achieved diamond valuation price principally through a correction which is applied for the absence of large diamonds which are typically under-represented in exploration scale samples.

Consistent with prior valuations, WWW are recommending the adoption of a single diamond price model for the Renard 2 and Renard 3 valuation samples given the similarity of the diamonds in terms of diamond qualities and size distribution. This base case price model is US$182/carat, a 56% increase compared to the price model of US$117/carat established in September 2009. Also consistent with past practice, a separate diamond price model has been adopted for the Renard 4 valuation sample given its apparently finer distribution of diamond sizes. The Renard 4 base case price model is US$112/carat, a 49% increase compared to the previously established price model of $75/carat.

For each diamond sample, WWW's own achieved diamond price was higher than the average of the five valuations upon which the base case diamond price model was established. WWW has been involved in the valuation of Canadian diamond production for mining royalty assessment purposes since 1998, and has valued all Canadian diamond production since that date. In this capacity, part of their mandate is to determine the maximum possible price that a parcel of diamonds might obtain when sold in the open market. It is their opinion, therefore, that "the base case model prices that have been determined are approximately 10% lower than might be expected should these same diamonds be offered for sale by tender in the current market."

Model Sensitivities and Diamond Price Assumptions

In establishing their diamond price models, WWW determine High and Minimum sensitivities on the base case diamond price based on alternate interpretations of diamond quality and size distribution. The WWW sensitivity limits are set such that it is highly unlikely that an actual diamond price achieved for each kimberlite body upon production would fall below the "Minimum" sensitivity, but it is possible that the actual diamond price achieved may be higher than the "High" sensitivity, which is not a maximum price.

For this exercise, separate High and Minimum sensitivities have been set for each sample valued. These sensitivities are US$163 to US$236/carat for Renard 2, US$153 to US$205/carat for Renard 3 and US$105 to US$185/carat for Renard 4.

As recommended by WWW, Stornoway will utilize a base case diamond price model of US$182/carat for the Renard 2 and 3 kimberlite pipes in the financial model of the Renard Feasibility Study. The sensitivities to the project's rate of return of using the "High" or "Minimum" prices will be demonstrated separately. In the case of Renard 4, a prior analysis has suggested that the apparently finer size distribution of diamonds in the Renard 4 valuation sample, which accounts for that sample's lower valuation result, is attributable to increased diamond breakage and poor plant performance during recovery. On this basis, the Renard 2 and Renard 3 diamond price was also adopted for Renard 4 during the recent declaration of the project's National Instrument 43-101 compliant Mineral Resource (Stornoway press release dated January 24, 2011). It is expected that a similar approach will be taken in the determination of an applicable diamond price for Renard 4 in the upcoming Feasibility Study.

About 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.

About the Renard Diamond Project

The Renard Diamond Project is located approximately 250 km north of the Cree community of Mistissini and 350 km north of Chibougamau in the James Bay region of North-Central Quebec. In May 2010, Stornoway filed a National Instrument 43-101 compliant technical report for the Preliminary Assessment at Renard that estimated the project to have the potential to produce approximately 30 million carats of diamonds over a 25 year mine life, with a pre-tax Net Present Value of C$885 million (at an 8% discount rate) and an Internal Rate of Return of 24.8%. National Instrument 43-101 compliant Indicated and Inferred Mineral Resources currently stand at 23.8 and 17.5 million carats respectively, with a further 23.5 to 48.5 million carats classified as a non-resource, "potential mineral deposit". All kimberlites remain open at depth. Total capital investment is currently estimated to be $511 million, with an average operating expenditure of approximately $67 million per year and a workforce of 300 people. Readers are referred to the technical report in respect of the Renard Diamond Project for further details and assumptions relating to the project.

On behalf of the Board

STORNOWAY DIAMOND CORPORATION

Matt Manson, President and Chief Executive Officer

This document contains "forward-looking information" within the meaning of Canadian securities legislation and "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995. This information and these statements, referred to herein as "forward-looking statements" are made as of the date of this document and the Company does not intend, and does not assume any obligation, to update these forward-looking statements, except as required by law.

Forward-looking statements relate to future events or future performance and reflect current expectations or beliefs regarding future events and include, but are not limited to, statements with respect to: (i) the amount of mineral resources and potential mineral deposits; (ii) the amount of future production over any period; (iii) net present value and internal rates of return of the proposed mining operation; (iv) capital costs, operating costs and diamond price assumptions; (v) mine expansion potential and expected mine life; (vi) expected time frames for completion of permitting and regulatory approvals, completion of a Feasibility Study and making a production decision; (vii) future exploration plans; and (viii) sources of and anticipated financing requirements. Any statements that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions or future events or performance (often, but not always, using words or phrases such as "expects", "anticipates", "plans", "projects", "estimates", "assumes", "intends", "strategy", "goals", "objectives" or variations thereof or stating that certain actions, events or results "may", "could", "would", "might" or "will" be taken, occur or be achieved, or the negative of any of these terms and similar expressions) are not statements of historical fact and may be forward-looking statements.

All forward-looking statements are based on Stornoway's or its consultants' current beliefs as well as various assumptions made by and information currently available to them. Many of these assumptions are set forth in the news release and include: (i) estimates of net present value and internal rates of return; (ii) estimates of potential production and duration of mine life; (iii) estimated completion date for the Feasibility Study and related Environmental and Social Impact Assessment; (iv) required capital investment and estimated workforce requirements; (v) receipt of regulatory approvals on acceptable terms within commonly experienced time frames; (vi) the assumption that a production decision will be made, and that decision will be positive; (vii) anticipated timelines for the commencement of mine production; (viii) anticipated timelines related to the Route 167 extension and the impact on the development schedule at Renard; (ix) anticipated timelines for community consultations and the conclusion of an Impact and Benefits Agreement; (x) market prices for rough diamonds and the potential impact on the Renard Project's value; (xi) future exploration plans and objectives. Although management considers these assumptions to be reasonable based on information currently available to it, they may prove to be incorrect. Many forward-looking statements are made assuming the correctness of other forward looking statements, such as statements of net present value and internal rate of return, which are based on most of the other forward-looking statements and assumptions herein. The cost information is also prepared using current values, but the time for incurring the costs will be in the future and it is assumed costs will remain stable over the relevant period.

By their very nature, forward-looking statements involve inherent risks and uncertainties, both general and specific, and risks exist that estimates, forecasts, projections and other forward-looking statements will not be achieved or that assumptions do not reflect future experience. We caution readers not to place undue reliance on these forward-looking statements as a number of important factors could cause the actual outcomes to differ materially from the beliefs, plans, objectives, expectations, anticipations, estimates assumptions and intentions expressed in such forward-looking statements. These risk factors may be generally stated as the risk that the assumptions and estimates expressed above do not occur, including the assumption in many forward-looking statements that other forward-looking statements will be correct, but specifically include, without limitation, risks relating to variations in the grade, kimberlite lithologies and country rock content within the material identified as mineral resources from that predicted, variations in rates of recovery and breakage; the greater uncertainty of potential mineral deposits, developments in world diamond markets, slower increases in diamond valuations than assumed, risks relating to fluctuations in the Canadian dollar and other currencies relative to the US dollar, increases in the costs of proposed capital and operating expenditures, increases in financing costs or adverse changes to the terms of available financing, if any, tax rates or royalties being greater than assumed, results of exploration in areas of potential expansion of resources, changes in development or mining plans due to changes in other factors or exploration results of Stornoway or its joint venture partners, changes in project parameters as plans continue to be refined, risks relating to receipt of regulatory approvals or settlement of an Impact and Benefits Agreement, the effects of competition in the markets in which Stornoway operates, operational and infrastructure risks and the additional risks described in Stornoway's most recently filed Annual Information Form, annual and interim MD&As, and Stornoway's anticipation of and success in managing the foregoing risks. Stornoway cautions that the foregoing list of factors that may affect future results is not exhaustive. When relying on our forward-looking statements to make decisions with respect to Stornoway, investors and others should carefully consider the foregoing factors and other uncertainties and potential events. Stornoway does not undertake to update any forward-looking statement, whether written or oral, that may be made from time to time by Stornoway or on our behalf, except as required by law.

SOURCE: Stornoway Diamond Corporation

Stornoway Diamond Corporation
Matt Manson
President and CEO
416-304-1026
Stornoway Diamond Corporation
Nick Thomas
Manager Investor Relations
604-983-7754 or Toll Free at 1-877-331-2232
info@stornowaydiamonds.com
Stornoway Diamond Corporation
M. Ghislain Poirier
Vice-president Affaires publiques
418-780-3938
gpoirier@stornowaydiamonds.com
www.stornowaydiamonds.com