Mountain Province Diamonds Inc T.MPVD

June Sale Results

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Mountain Province Diamonds Results of Fifth Diamond Sale of 2018

Toronto and New York, June 28, 2018 – Mountain Province Diamonds Inc. (“Mountain Province”, the “Company”) (TSX and NASDAQ: MPVD) today announces the results of its recently completed fifth diamond tender sale of 2018. Total proceeds from the sale were US$30.3 million (CDN$40.0 million), setting another new high for Mountain Province’s tender results to date. This tender also delivered the sale of Mountain Province’s highest value individual diamond, as well as the highest attributable value per tonne to date.

The results of the fifth tender sale, with preceding sale results for comparative context, are summarized as follows:

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Tender Sale Proceeds (USD million) Carats Sold (‘000s)
Value per Carat (USD)1
Normalized Value per Carat (USD)2

2017-H1 Sales 1-5

71.5 892 80 75

2017-Q3 Sales 6-7

48.0 753 64 78

2017-Q4 Sales 8-10

59.3 1,005 59 66

2018-Q1 Sales 1-2

52.4 527 99 83

2018 Apr Sale 3

26.4 451 59 80

2018 May Sale 4

28.3 350 81 79

2018 Jun Sale 5

30.3 356 85 86

1

Diamonds sold at individual sale events will not directly reflect run-of-mine production from specific processing periods. The timing of the sale of some goods may be accelerated or deferred for tactical marketing purposes. Realized average value per carat is also impacted by the binary nature of the fancies and specials bidding process within each production split, conducted approximately every five weeks with the Company’s joint venture partner, De Beers Canada Inc. The winning party of each fancies and specials bid then markets 100% of those diamonds.

2
Beers Canada Inc.

Normalized to adjust for goods accelerated or deferred, and to include fancies and specials acquired through bid by De

“The positive results of our fifth sale were driven by strong demand in the rough diamond market”, said Reid Mackie, the Company’s Vice President Diamond Marketing. “This demand is supported by stable rough supply levels and continued positive retail news from the key diamond consumer markets. At our fifth tender, customer interest and bidding competition was particularly high for larger white gem lots. We saw prices for this product category again increase by low single digit percentages compared with the previous sale.”

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This interest in larger white gem was exemplified by the impressive sales result achieved for the 95 carat diamond acquired at the most recent joint venture production split. Said Mr. Mackie, “Customer competition for the 95 carat gem exceeded expectations, with the final result more than doubling the previous highest value achieved for a single diamond. To maintain confidentiality for the buyer, further specifics of this diamond’s sale will not be released.”

To more meaningfully relate prices realized at sale events to production results, the Company also provides the following table:

Production Period3

Sale in Which Goods Were Primarily Sold

Tonnes Processed (100%) (‘000s) Recovered Grade (carats per tonne) Carats Recovered (100%) (‘000s) Carats Recovered (49% share) (‘000s) Attributed Value per Tonne in CAD1

H1 Q3 Q4 Jan Feb Mar Apr May

2017 2017

3 to 7 & Partial 8 Partial 8 to10 1,259 823 1.97 2.22 2,481 1,825 1,216 894 183 172

Attributed Value per Tonne has been determined based
adjusted to their period of production, reflecting only the Company’s 49% share of all diamonds including fancies and specials.
Not applicable as goods from this production period have not yet been sold.
Total figures may differ slightly from the sum of monthly figures due to the effects of rounding.

Plant throughput in the month of May was over 339,000 tonnes, the highest throughput reported for a production month since inception. The recovered grade for May of 1.84 carats per tonne reflects a short-term sequencing impact as ore processed for the month included a higher than typical proportion of 5034 Centre lobe material, which tends to be lower in grade but higher in average value per carat.

Said Jonathan Comerford, the Company’s Interim President and Chief Executive Officer, “The fifth sale of the year saw a strong performance for Mountain Province in sales and pricing, reflecting the growth in appreciation of our production by our customers as well as a continued strong rough diamond market. We set a new record for total proceeds realized by Mountain Province in a tender, and the normalised value for this sale at US$86 a carat is one of the highest we have achieved to date. This tender also saw the successful sale of our highest value diamond to date, at a price we were very happy with.”

Continued Mr. Comerford, “The attributed value per tonne for the fifth sale at $234 for March is also the highest we have achieved to date and highlights the Company’s very high operating margins. We view value per tonne as a better performance measure for the Company than value per carat as it takes into account the improved grade versus the original plan as well as the effect of current exchange rates. The mine and plant operations continue to perform well, with carats produced to date ahead of plan and considerably ahead of this time last year.”

2017 2018 2018 2018

2018 2018

n/a2 n/a2

275 339 2.31 1.84 634 624 311 306

n/a2 n/a2

1, 2 2&3 4 &3
693 327 217

2.35 1.89 2.05 1,627 618 444 797 303 218 208 167 185

5

242 2.40 579 284

234

1

2 3

on realized sale results, with any

accelerated or deferred goods

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As previously announced, Stuart Brown will start as the Company’s new President and CEO on July 1st. Said Mr. Comerford, “The Board very much looks forward to working with Stuart, and would again like to thank David Whittle for steering the Company through a critical 12 months of transition.”

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Mountain Province Diamonds is a 49% participant with De Beers Canada in the Gahcho Ku diamond mine located in Canada’s Northwest Territories. Gahcho Ku is the world’s largest new diamond mine, consisting of a cluster of four diamondiferous kimberlites, three of which are being

developed and mined under the initial 12 year mine plan.

Qualified Person

The disclosure in this news release of scientific and technical information regarding Mountain Province’s mineral properties has been reviewed and approved by Keyvan Salehi, P.Eng., MBA, a Qualified Person as defined by National Instrument 43-101 Standards of Disclosure for Mineral Projects.

FOR FURTHER INFORMATION, PLEASE CONTACT:

Mountain Province Diamonds Inc.
Keyvan Salehi
Director, Investor Relations and Engineering Services 161 Bay Street, Suite 1410
Toronto, Ontario M5J 2S1

Phone: [phone]
E-mail: [e-mail]

Caution Regarding Forward Looking Information

This news release contains certain “forward-looking statements” and “forward-looking information” under applicable Canadian and United States securities laws concerning the business, operations and financial performance and condition of Mountain Province Diamonds Inc. Forward-looking statements and forward-looking information include, but are not limited to, statements with respect to estimated production and mine life of the project of Mountain Province; the realization of mineral reserve estimates; the timing and amount of estimated future production; costs of production; the future price of diamonds; the estimation of mineral reserves and resources; the ability to manage debt; capital expenditures; the ability to obtain permits for operations; liquidity; tax rates; and currency exchange rate fluctuations. Except for statements of historical fact relating to Mountain Province, certain information contained herein constitutes forward-looking statements. Forward-looking statements are frequently characterized by words such as “anticipates,” “may,” “can,” “plans,” “believes,” “estimates,” “expects,” “projects,” “targets,” “intends,” “likely,” “will,” “should,” “to be”, “potential” and other similar words, or statements that certain events or conditions “may”, “should” or “will” occur. Forward-looking statements are based on the opinions and estimates of management at the date the statements are made, and are based on a number of assumptions and subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking statements. Many of these assumptions are based on factors and events that are not within the control of Mountain Province and there is no assurance they will prove to be correct.