16 March 2023 DISCLAIMER This presentation is confidential and is being made only to, and is only directed at, persons to whom this presentation may lawfully be communicated (“relevant persons”). Any person who is not a relevant person should not act or rely on this presentation or any of its contents. Information in this presentation relating to the price at which relevant investments have been bought or sold in the past or the yield on such investments cannot be relied upon as a guide to the future performance of such investments. This presentation does not constitute an offering of securities or otherwise constitute an invitation or inducement to any person to underwrite, subscribe for or otherwise acquire securities in any company within the Gem Diamonds Group (the “Group”). Neither this document nor the fact of its distribution nor the making of the presentation constitutes a recommendation regarding any securities. This presentation is for information purposes only and accordingly, no Company within the Group, nor any of their respective directors, employees, agents or advisers make any representation or warranty in respect of the contents of this presentation or otherwise in relation to the Group or any of its businesses. This presentation contains forward-looking statements which are subject to risks and uncertainties because they relate to future events. These forward-looking statements include, without limitation, statements in relation to the Group’s projected growth opportunities. Some of the factors which may cause actual results to differ from these forward-looking statements are discussed in certain slides of this presentation and others can be found by referring to the information contained under the heading “Risk Management” in our Annual Report for the year ended 31 December 2022 which can be found on our website (www.gemdiamonds.com). The forward-looking information contained in this presentation is expressly qualified by this cautionary statement. The information contained in this presentation is subject to amendment, revision and updating, and such information may change materially. No person is under any obligation to update, or keep current, the information contained in this presentation, and any opinions expressed in relation thereto are subject to change without notice. This presentation has not been independently verified and no representation or warranty, express or implied, is made as to the fairness, accuracy or completeness of the information or opinions contained herein. No statement in this presentation is intended as a profit forecast or profit estimate and no statement in this presentation should be interpreted to mean that earnings per share for the current or future financial years would necessarily match or exceed the historical published earnings. This presentation also contains certain non-IFRS financial measures. The Group’s management believes these measures provide valuable additional information in understanding the performance of the Group or the Group’s businesses because they provide measures used by the Group to assess performance. However, this additional information presented is not uniformly defined by all companies, including those in the Group’s industry. Accordingly, it may not be comparable with similarly titled measures and disclosures by other companies. Additionally, although these measures are important in the management of the business, they should not be viewed in isolation or as replacements for or alternatives to, but rather as complementary to, the comparable IFRS measures such as revenue and other items reported in the consolidated financial statements. The distribution of this presentation or any information contained in it may be restricted by law in certain jurisdictions, and any person into whose possession any document containing this presentation or any part of it should inform themselves about, and observe such restrictions on information contained in this presentation. Any securities mentioned herein have not been and will not be registered under the United States Securities Act of 1933, as amended and may not be offered, sold, resold or delivered, directly or indirectly, in or into the United States without registration or exemption. The information contained herein is correct as at 15 March 2023. 2 Gem Diamonds Limited Full Year Results 2022 2022 IN REVIEW Revenue US$188.9 million EBITDA US$43.7 million Carats recovered 106 704 Basic earnings per share 7.3 US cents All injury frequency rate 0.70 Net cash position US$3.3 million Decarbonisation target 30% by 2030 US$ per carat achieved US$1 755 Dividend & share buyback US$4.8 million 3 Gem Diamonds Limited Full Year Results 2022 2022 KEY STRATEGIC PRIORITIES PRODUCE THE BEST DIAMONDS, IN THE BEST WAY, LEAVING A LASTING LEGACY EXTRACTING MAXIMUM VALUE FROM OUR OPERATIONS WORKING RESPONSIBLY AND MAINTAINING OUR SOCIAL LICENCE PREPARING FOR OUR FUTURE • Optimise operating model: • Reduced waste hauling distances • Maturing organisational safety culture continued • Underground Feasibility Study • Long-term mine planning • Adopted ICMM's Global and optimisation • Implemented steeper slopes in Main pit • Reduced waste tonnes mined • Short-term mine planning • Surface miner trials completed Industry Standard on Tailings Management • Strengthened long-term relationships with all stakeholders • Advanced 5-year needs-based CSI investment strategy • External growth opportunities • Phase 2 of three-year TCFD strategy implemented • Decarbonisation target set • Renewable energy plan 4 4 Gem Diamonds Limited Full Year Results 2022 DIAMOND MARKET THE DIAMOND MARKET IMPROVED IN 2022 GLOBAL ECONOMIC BACKDROP DIAMOND MARKET • Global economic growth of 3% • Strong demand throughout 2022 • Sanctions on Russia (Alrosa) caused diamond supply shortage in smaller goods • Slight softening of diamond prices seen in Q4 2022 • Luxury jewellery brands performed exceptionally well in 2022 • Significant impact of the Russian/Ukrainian war: • Diesel prices • Supply chains disrupted • Explosives and other consumable prices • Commodity prices • Inflation • China re-opening post COVID in Q4 2022 - expected rebound in economic activity 5 5 Gem Diamonds Limited Full Year Results 2022 GEM DIAMONDS’ MARKET POSITION • Highest US$ per carat kimberlite producer • Strong prices achieved for large high-value diamonds • Strong demand and competitive bidding throughout the year • Price increases for <5 carat diamonds seen in 2022 • Opportunities to capture downstream value continued 6 6 Gem Diamonds Limited Full Year Results 2022 OUR APPROACH TO CLIMATE CHANGE • Completed Phase 2 of TCFD roadmap • Advanced the materiality assessment of relevant physical and transition climate-related risks • Developed and adopted carbon-pricing model • Established Decarbonisation and Energy Committee to: • Assess lower-carbon and renewable energy sources • Drive our newly adopted decarbonisation strategy Outcomes Scope 1 (fossil fuels) Scope 2 (grid) Achievements • Further reduced waste rock hauling distances • Reduced waste mining volumes (steeper slopes) • 18% net reduction in Scope 1 carbon emissions • Implemented energy use efficiency initiatives in processing plants • Optimised lighting and heating energy consumption • Improved energy demand management • 24% net reduction in carbon emissions 7 Gem Diamonds Limited Full Year Results 2022 • 31% reduction in total energy consumption ‘Best Climate-Related Reporting (Small Cap)’ award • OUR DECARBONISATION STRATEGY COMMITTED TO 30% REDUCTION BY 2030 • Letšeng accounts for 98% of Group carbon footprint • Targeting a 30% reduction of Scope 1 and 2 emissions (against our 2021 footprint) • Two key levers to achieve this: • Reduce energy consumption through process and equipment efficiencies • Replace fossil fuel-based energy with lower-carbon and renewable energy sources 8 Gem Diamonds Limited Full Year Results 2022 9 9 Gem Diamonds Limited Full Year Results 2022 ZERO HARM IS A PRIORITY • Organisational safety maturity strategy advanced • Improved safety performance in 2022: • Zero fatalities and three LTIs • AIFR: 0.70 • No major or significant environmental incidents • No major or significant social incidents • Aligned to Global Industry Standard on Tailings Management • Zero incidents of compromised dam or TSF integrity 10 10 Gem Diamonds Limited Full Year Results 2022 All injury frequency rate (AIFR)1.450.930.760.930.7020182019202020212022Lost time injury frequency rate (LTIFR)0.150.280.040.240.1320182019202020212022 11 11 Gem Diamonds Limited Full Year Results 2022 2022 CSR OVERVIEW • Successful implementation of 2022 CSI strategy: • Water and sanitation infrastructure • Tertiary scholarships and improved infrastructure at schools • Lesotho Legend egg project operational • Small and medium enterprise development • Advanced bioremediation project • Retained ISO 14001 and ISO 45001 certification (for six consecutive years) • Retained FTSE4Good status for 4th consecutive year • UN Global Compact member - integration of six adopted UN SDGs 12 12 Gem Diamonds Limited Full Year Results 2022 COMMUNITY MEMBERS 13 13 Gem Diamonds Limited Full Year Results 2022 OPERATIONS REVIEW • Focus on reducing operating costs and decarbonisation • Reduced waste volumes (steeper slopes in Main pit) • Reduced waste haulage distances • Ore tonnes treated impacted primarily by: • AV contract expired 30 June • Electricity grid interruptions • Lesotho national elections 2-day shutdown • Carats recovered in line with expected grade from treated ore 14 14 Gem Diamonds Limited Full Year Results 2022 Waste tonnes mined (millions)262416191020182019202020212022Ore tonnes treated (millions)6.56.75.46.25.520182019202020212022Carats recovered (thousands)12711410111510720182019202020212022 OPERATIONS REVIEW continued Frequency of large diamond recoveries 2022 2021 2008 – 2021 FY average 4 18 69 108 507 706 6 16 81 122 570 795 8 19 77 114 442 660 Weight category >100 carats 60 – 100 carats 30 – 60 carats 20 – 30 carats 10 – 20 carats Total diamonds >10 carats • Projects: • Replacement of the PCA - completion date Q2 2023 • Resource and Reserve Statement - completion date Q4 2023 2020 Resource core drilling programme completed • Underground Feasibility Study - completion date Q4 2023 15 15 Gem Diamonds Limited Full Year Results 2022 LONG-TERM MINE PLAN • Implementation of steeper slopes and continued mining optimization in the Main pit: • Reduced waste volumes of c.2.7 million tonnes over LoM • Increased ore volumes of c.5.3 million tonnes over LoM • Further reduced waste haulage distances • Satellite pipe contact position: • Urgent change in pit design required for safety reasons • Deferment of c.1.9 million ore tonnes of C5W into C6W / Underground • C5W mining ends in 2024 (excluding any additional tonnes from end of cutback mining) • Revised waste mining profile: • 2023 - decreased to c.10.0 million tonnes p.a. • 2024 - ramping up to c.23.0 million tonnes p.a. (subject to trade-off studies below) • Ore mining remains constant at c.5.6 million tonnes p.a. from 2024 • Life of mine to 2040 • Underground Feasibility Study commenced in July 2022 scheduled to be completed in Q4 2023 • Resource & Reserve Statement scheduled to be completed by end of 2023 • Open pit vs underground mining trade-off studies to be completed in 2023 16 16 Gem Diamonds Limited Full Year Results 2022 LONG TERM MINE PLAN continued % 17 Gem Diamonds Limited Full Year Results 2022 SALES AND MARKETING • Achieved US$1 755 per carat • Sold 4 diamonds greater than 100 carats • Sold 29 diamonds for more than US$1.0 million • Sold 83 diamonds for more than US$20 000 per carat • >10.8 carat diamonds contributed 69% of revenue • Dubai viewings in March and September • Targeted supply to premium, luxury brands % 18 Gem Diamonds Limited Full Year Results 2022 Average US$ per carat2 1311 6371 9081 8351 75520182019202020212022Revenue per size fraction691615>10.8cts5-10 cts<5 cts SIGNIFICANT DIAMOND RECOVERIES IN 2022 244 CARAT WHITE DIAMOND 127 CARAT WHITE DIAMOND 99 CARAT WHITE DIAMOND 30 CARAT WHITE DIAMOND (HIGHEST WHITE $/CT) 92 CARAT WHITE DIAMOND 10 CARAT PINK DIAMOND (HIGHEST $/CT) 19 19 Gem Diamonds Limited Full Year Results 2022 20 20 Gem Diamonds Limited Full Year Results 2022 INCOME STATEMENT US$ million Revenue from contracts with customers Royalties and selling costs Cost of sales COVID-19 related costs Corporate expenses Underlying EBITDA Depreciation and mining asset amortisation Other operating expenses Net finance costs Non-cash items Profit before tax for the year Income tax expense Profit after tax for the year Non-controlling interests Attributable profit Earnings per share (US cents) Dividends per share (US cents) 2022 188.9 (20.3) (116.2) (0.1) (8.6) 43.7 (8.4) (2.4) (4.1) 1.6 30.4 (10.2) 20.2 (10.0) 10.2 7.3 – 2021* 201.9 (21.9) (113.5) (0.7) (8.4) 57.4 (8.6) (3.3) (4.0) 1.5 43.0 (15.6) 27.4 (12.6) 14.8 10.5 2.7 % Variance (6) (24) (29) (26) (30) (100) *The prior year figures have been re-presented, as Gem Diamonds Botswana (Proprietary) Limited (Ghaghoo Diamond Mine) ceased to be classified as a discontinued operation during the current financial reporting period. 21 Gem Diamonds Limited Full Year Results 2022 LETŠENG COST ANALYSIS Ore tonnes treated (millions) Operating Costs Direct cash costs¹ Plant 3 operator costs Total direct cash operating costs Non-cash accounting charges² Total operating cost per tonne treated – LSL Average foreign exchange rate Total operating cost per tonne treated – US$ Waste tonnes mined (millions) Total waste cash costs per waste tonne mined – LSL Average foreign exchange rate Total waste cash costs per waste tonne mined – US$ 2022 5.5 252.50 10.57 263.07 82.02 345.09 16.37 21.08 10.2 66.74 16.37 4.08 2021 6.2 185.59 15.53 201.12 70.63 271.75 14.79 18.38 18.7 44.44 14.79 3.00 % Variance (11) 31 27 15 (46) 50 36 1 2 22 Direct mine cash costs represent all operating costs, excluding royalty and selling costs. Non-cash accounting charges include waste stripping cost amortised, inventory and ore stockpile adjustments, finance lease costs, and excludes depreciation and mining asset amortisation. Gem Diamonds Limited Full Year Results 2022 FINANCIAL POSITION US$ million Non-current assets IFRS 16 Right of use assets Current assets Income tax receivable Cash Total assets Equity attributable to the parent company Non-controlling interest Total equity Interest-bearing loans and borrowings (long and short term) IFRS 16 lease liabilities (long and short term) Non-current liabilities Deferred tax liabilities Current liabilities Liabilities associated with assets held for sale Total liabilities 2022 313.6 6.3 35.2 2.3 8.7 366.1 152.6 80.4 233.0 5.9 7.9 17.6 82.0 19.7 – 133.1 2021 312.0 3.1 35.3 1.2 30.9 382.5 159.8 86.9 246.7 11.0 4.8 13.3 82.5 22.2 2.0 135.8 % Variance (4) (6) (2) 23 23 Gem Diamonds Limited Full Year Results 2022 CASH MANAGEMENT • Group cash of US$8.7 million • Net cash of US$3.3 million • Available facilities at year end - US$82.6 million 24 24 Gem Diamonds Limited Full Year Results 2022 Corporate costs (excl depreciation) (US$ millions)10.09.17.58.48.620182019202020212022 LETŠENG 2023 GUIDANCE Waste stripped (Mt) Ore treated (Mt) Satellite pipe ore contribution¹ (Mt) Carats recovered (Kct) Carats sold (Kct) Direct cash costs (before waste) per tonne treated² (Maloti) Operating costs per tonne treated³ (Maloti) Mining waste cash costs per tonne of waste mined (Maloti) Total capital4 (US$ million) 2023 Guidance 9 – 11 5.15 – 5.35 2.8 – 3.0 104 – 107 102 – 105 250 – 270 345 – 365 65 – 70 13 – 15 1 The contribution from Satellite pipe material is evenly spread throughout the year. 2 Direct cash costs excludes royalty and selling costs. 3 Operating costs comprise direct cash costs, waste stripping cost amortised, inventory and ore stockpile adjustments, depreciation and mining asset amortisation and finance lease costs. 4 At an exchange rate of US$1: LSL17.50. 25 25 Gem Diamonds Limited Full Year Results 2022 26 26 Gem Diamonds Limited Full Year Results 2022 2023 FOCUS AREAS EXTRACTING MAXIMUM VALUE FROM OUR OPERATIONS WORKING RESPONSIBLY AND MAINTAINING OUR SOCIAL LICENCE PREPARING FOR OUR FUTURE • Short-term mine planning • Underground Feasibility Study • Right-sizing of Letšeng • PCA replacement project • Surface miner project • Phase 3 of TCFD recommendations • Bioremediation project • 5-year CSI investment strategy • Organisational safety culture • Resource & Reserve Statement • Premium luxury brands • External growth and expansion opportunities • Decarbonisation • Lower carbon • Renewable energy 27 27 Gem Diamonds Limited Full Year Results 2022 CONTACT US Gem Diamonds Limited Glenn Turner / Susan Wallace T: +44 (0) 203 043 0280 IR@gemdiamonds.com Celicourt Communications Mark Antelme / Felicity Winkles T: +44 (0)20 8434 2643 28 Gem Diamonds Limited Full Year Results 2022 APPENDIX A: MARKET INFORMATION Gem Diamonds Limited is listed on the Main Board of the London Stock Exchange LSE: GEMD Daily average trading volume across all platforms in 2022 Shares in issue (excl. treasury shares) Free float (excl. holders above 5%, ESOP and Directors’ holdings) (%) Share price (15 March 2023) 170k 139 403 591 30.8 £0.27 Market capitalisation (millions) £38/US$46 Major shareholders Sustainable Capital Limited Graff Investments Limited Lansdowne Partners Ltd Aberforth Partners LLP Gem Diamonds Holdings Ltd Hosking Partners LLP Ruffer LLP Dimensional Fund Advisors As at 15 February 2023 (%) 21.9 15.0 13.4 12.1 6.7 3.6 2.9 2.6 Company officers Clifford Elphick Chief Executive Officer Glenn Turner Chief Legal and Commercial Officer Michael Michael Chief Financial Officer Brandon de Bruin Chief Operating Officer 29 Gem Diamonds Limited Full Year Results 2022 2022 Share price movement Price Volume 24324048566472800.000.801.602.40