Mountain Province Diamonds Announces Third Quarter 2025 Production and Sales Results, Update on Guidance, Details of Third Quarter 2025 Earnings Release, and Conference Call

Press Release

TORONTO, Nov. 6, 2025 – Mountain Province Diamonds Inc. (“Mountain Province”, the “Company”) (TSX: MPVD) (OTC: MPVD) today announces production and sales results for the third quarter ended September 30, 2025 (“the Quarter” or “Q3 2025”) from the Gahcho Kué Diamond Mine (“GK Mine”). All figures are expressed in Canadian dollars unless otherwise noted.

Q3 2025 Production Takeaways
(all figures reported on a 100% basis unless otherwise stated)

• 1,000,887 carats recovered, 16% lower than Q3 2024: 1,187,912 carats.
• 1.18 Average grade of carats per tonne, a 12% decrease compared to Q3 2024: 1.24 carats per tonne.
• 807,458 ore tonnes mined; a 13% reduction compared to Q3 2024: 923,814 ore tonnes mined.
• 847,024 tonnes treated, a 12% decrease compared to Q3 2024: 961,371 tonnes treated.

Q3 2025 Production Figures
	2025 Q3	2024 Q3	YoY Variance
Total tonnes mined (ore and waste)	9,922,231	8,603,369	+15 %
Ore tonnes mined	807,458	923,814	-13 %
Ore tonnes treated	847,024	961,371	-12 %
Carats recovered	1,000,887	1,187,912	-16 %
Carats recovered (49% share)	490,434	582,077	-16 %
Recovered grade (carats per tonne)	1.18	1.24	-4 %

Update on 2025 Guidance

In the Company’s quarterly Management Discussion and Analysis (MD&A) we provide guidance targets in respect of production and cost metrics for the 2025 fiscal year, which include, carats recovered and production costs per carat recovered and per tonne treated. We wish to issue revised guidance in respect of these three metrics only.

The reduction in carats recovered, is due to lower than planned grade from the ore stockpile material treated, resulting in a revised guidance range of 4.0 million to 4.2 million carats recovered, compared to previous guidance of 4.3 million to 4.7 million carats recovered.

In respect of production costs, although operating costs remain largely in line with budget, the combination of lower carats recovered and the release of previously capitalised costs into production costs as ore stockpile tonnes reduce, pushed the production costs per carat beyond the top end of guidance, with a revised guidance range of $125 – $130 per carat recovered, compared to original guidance of $92 – $107 per carat recovered. The reduction in the tonnes of ore stockpile, similarly, explains the revised guidance range of $145 – $155 per tonne treated, compared to original guidance of $120 – $137 per tonne treated.

Q3 2025 Sales Results

In the Quarter, 409,081 carats were sold for $29.2 million (US$21.2 million), averaging $71 per carat (US$52 per carat). By comparison, in Q3 2024, 679,599 carats were sold for $69.4 million (US$50.8 million), averaging $102 per carat (US$75per carat).

Mark Wall, the Company’s President and Chief Executive Officer, commented:

“Q3 2025 was a very important quarter for the operations as we completed the waste stripping to the top of the 5034-NEX orebody and mined the transitional phase of the top of the orebody.  Mining during the period was constrained by the space available as operations focussed on access to the higher-grade orebody.

Tonnes processed were slightly lower in Q3 2025 than Q2 2025 due to a planned 5-day shutdown in September to complete scheduled maintenance works.

The grade processed in Q3 2025 increased to 1.18 carats per tonne, from Q2 2025 grade which had a processed grade of 0.8 carats per tonne.  This was due to the processing of the transitional portions of the higher grade 5034-NEX orebody, which moved the overall grade up, even though we continued to treat some low-grade ore stockpiles in the Quarter.  As a result, the carats recovered increased when compared to Q2 2025.

I am pleased to say that subsequent to the end of Q3 2025 we have successfully mined into sustained 5034-NEX material and this high-grade material is running well through the processing plant, which is planned to lead to substantially higher carat production for Q4 2025 and 2026.

The diamond market has remained constrained by the tariffs and related trade negotiations between the United States and India.  Any near-term  improvement in price largely depends on the United States and India reaching a trade deal.”

Earnings Release and Conference Call Details

The Company will host its quarterly conference call on Wednesday November 12th, 2025, at 11:00am ET. Prior to the conference call, the Company will release Q3 2025 financial results on November 11th, 2025 after-market.

Conference Call Dial-in Details:

Title: Mountain Province Diamonds Inc Q3 2025 Earnings Conference Call

Conference ID: 41267
Date of call: 11/12/2025
Time of call: 11:00 Eastern Time
Expected Duration: 60 minutes

Webcast Link: https://app.webinar.net/MBLmj14DGoe
Participant Toll-Free Dial-In Number:             (+1) 888-699-1199
Participant International Dial-In Number:       (+1) 416-945-7677

A replay of the webcast and audio call will be available on the Company’s website.

For further information: FOR FURTHER INFORMATION, PLEASE CONTACT: Mark Wall, President and CEO, 151 Yonge Street, Suite 1100, Toronto, Ontario M5C 2W7, Phone: (416) 361-3562, E-mail: info@mountainprovince.com

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