Southstone Minerals REPORTS Q2 2026 DIAMOND SALES...

Southstone Minerals Limited 2751 Graham Street

Victoria, British Columbia, V8T 3Z1 TSX Venture : SML https://www.southstoneminerals.com

• Gross diamond sales: US$3,713,181 (vs. US$1,903,889; +95%)
• Carats sold: 1,390.42 (vs. 897.24; +55%)
• Average price: US$2,671/ct (vs. US$2,122/ct; +26%)
• Price distribution: 13 diamonds achieved individual prices >US$5,000/ct "Specials" (diamonds >10.8 carats)

  Mining of basal gravel layers has resulted in the recovery of "Specials" (diamonds greater than 10.8 carats). In the quarter:

• 22 Specials were sold, averaging 19 carats each, for total proceeds of US$2,774,934.

• The largest was a 38.247-carat diamond that sold for US$616,197 (US$16,111 per carat).

• This is the highest individual diamond sale price recorded by the Company since it acquired Oena in 2014.

• Since November 2023, Specials have represented 29% of recovered carats and 67% of gross sales value from the Sandberg Section.

  Inventory
• Unsold Inventory: The Company enters the next fiscal quarter with an additional 305.1 carats, including five Specials, in unsold inventory from late February production. Sandberg Section Sales

  Sandberg Section mining period	Total carats sold	Total Number of Diamonds	Average Diamond Size (carats)	US ($) per carat	Gross Diamond Sales US ($)
  Sep 2018 to Nov 2021	2,690	1,157	2.33	-	-
  Nov 2023 to Aug 2024	769	319	2.41	1,935	1,488,052
  Apr 2025 to Feb 2026	3,689	1,258	2.93	2,171	8,009,655

  Table 1 - Sandberg Section 2018 to Q2 2026 diamond sales. An additional 305.1 carats of late Q2 2026 production (February 21-28, 2026) remains in inventory for future tender sale. Note: Gross diamond sales represent total tender proceeds before tender costs. Any inconsistencies between the totals shown are due to rounding.

  Q2 2026 Tenders

  African Star Minerals (Pty) Ltd. ("African Star" or "ASM"), a 43%-owned subsidiary of Southstone, is party to a Contract Mining and Diamond Recovery Agreement with mining contractor Rietput Delwery BK ("Rietput"). Effective July 1, 2025, Gross Diamond Sales (net of tender costs) are split 80:20 between Rietput and African Star when individual tender sales equal or exceed ZAR 10,000,000. If a tender sells for less than ZAR 10,000,000, the split is 85:15 between Rietput and African Star.

  Tender / Date	Carats sold	Gross tender proceeds (before tender costs) US ($)	Revenue split applied to Rietput & ASM	Effective economic interest in ASM share (43% of ASM net tender proceeds)
  273 / Jan 22, 2026	414.87	587,759	85:15	6.45%
  274 / Feb 19, 2026	975.55	3,025,422	80:20	8.60%
  Total	1,390.42	3,713,181

  Table 2 - Q2, 2026 Tender results and revenue split applied. Revenue split is applied to tender proceeds net of tender costs; gross proceeds are shown before tender costs.

  Oena Mine Performance

  Oena mining period	Total carats sold	Total Number of Diamonds	Average Diamond Size (carats)	US ($) per carat	Gross Diamond Sales US ($)
  Jul 2015 to Feb 2026	13,332	6,006	2.22	1,773	23,637,579

  Table 3 - Oena Mine 2015 to 2026 diamond sales. An additional 305.1 carats of late Q2 2026 production (February 21-28, 2026) remains in inventory for future tender sale. Note: Gross diamond sales represent total tender proceeds before tender costs. Any small inconsistencies between the totals shown are due to rounding.

  Southstone, through African Star, provides operational oversight at Oena, including diamond sales administration, contractor liaison, mining license compliance, and security. The Company maintains a management and security team in South Africa, including the CEO of African Star and the Oena Operational Site Manager. The Company's Executive Chairman, with external geological support, provides operational support for internal reporting of Oena activities and provides geological and technical support to the operations team and contractors.

  Botswana Uranium Acquisition Update

  Further to its news releases of February 18, July 21 September 12, 2025, Southstone Minerals Limited announces that it has entered a third addendum (the "Third Addendum") to the binding term sheet with Afrium Energy Pte. Ltd. ("Afrium").

  The Third Addendum extends the End Date of the acquisition agreement to September 12, 2026, to allow additional time for the renewal of the three prospecting licences in the Republic of Botswana. All other terms of the agreement remain unchanged and in full force.

  Southstone recognizes that licence renewals in Botswana can be a lengthy administrative process. The Company, together with Afrium, is actively working with the relevant authorities to ensure the renewals are completed in due course. The Company remains committed to advancing this strategic transaction while continuing to focus on its core operations at the Oena Diamond Mine.

  Corporate Update

  The Company confirms it is not currently in compliance with Exchange Policy 3.1 and 3.2 requirements regarding the composition of the Board and appointment of officers but is acting in good faith and continues to operate responsibly while working toward full compliance. The Company expects/intends to restore compliance upon closing (subject to closing/TSXV acceptance) of the Afrium transaction. At that time, the Company will:

• Appoint a Chief Financial Officer separate from the CEO; and

• Appoint at least one additional independent director, enabling the formation of a compliant Audit Committee.

The technical disclosure in this news release relating to diamond production, recovery and sales has been approved by Terry L. Tucker, P.Geo. (APEGBC), Executive Chairman, and a Qualified Person as defined by National Instrument 43-101 of the Canadian Securities Administrators. Mr. Tucker has verified the production and sales records disclosed in this release.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. Capitalized terms used herein that have not been defined have the same meanings ascribed in the policies of the TSX.V.

Certain statements in this news release may constitute "forward-looking statements" within the meaning of applicable securities laws. Forward-looking statements are not historical facts and include statements regarding expectations for continued production from the lower diamond-bearing gravel layer at Sandberg, the timing and results of future tenders, the characteristics of unsold diamond inventory, and ongoing operations at the Oena Diamond Mine. Forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results to differ materially from those expressed or implied.

These risks and uncertainties include, among others, fluctuations in global diamond prices and market demand, variations in the size, quality and quantity of recovered diamonds, contractor operational performance, the ability

to obtain or maintain required permits, consents or authorizations, movements in the ZAR/USD exchange rate affecting tender value thresholds, the Company's ability to raise capital to execute its business strategy, and the risks and uncertainties disclosed in the Company's most recent Management's Discussion and Analysis filed with Canadian securities regulators.

Readers are cautioned not to place undue reliance on forward-looking statements. Forward-looking statements are made as of the date of this news release, and the Company undertakes no obligation to update or revise them except as required by applicable securities laws.

Figure 1- Oena Diamond Mine Sandberg Special Size Diamonds sold in Q2 2026 (not to scale):