Star - Orion South Diamond Project & Fort à la Corne ......3 4 Diamond Results STAR UG, LDD & Trench Cutter 0 200 400 600 800 1000 1200 1400 1600 1800 +5 (0.049 ct) +7 (0.12 ct) +9

Star - Orion South Diamond Project & Fort à la Corne Diamond District

Comparison of Trench Cutter Diamond Results with

Star Underground and LDD

November 2020

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Star Trench and LDD HolesGrid = 50 metres

250m underground proximal radius

Diamond Results STAR UG, LDD & Trench Cutter

• The presentation focuses on the diamonds recovered from the EJF kimberlite unitthe first four trench cutter holes excavated on the Star Kimberlite

• To date 3,505 tonnes of EJF kimberlite from these four trenches has beenprocessed through the on-site BSP and the diamonds recovered from DMSconcentrates and XRT Accepts at the SRC

• 3,500 tonnes has been chosen for the plots in this presentation as it represents thetotal tonnage of the EJF processed to date from the first four trenches and is alsoequal to the tonnage recovered from the 48 inch LDD holes proximal to the Starunderground, within a 250 metre a radius of the center of the Star underground

• To date, FTIR diamond typing has been completed on EJF diamonds for the firstthree trenches

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+5 (0.049 ct) +7 (0.12 ct) +9 (0.18 ct) +11 (0.32 ct) 3gr (0.66 ct)

STONES PER 3,500 TONNES vs DIAMOND SIZE CLASS

STAR UG EJF STAR LDD EJF INNER STAR LDD EJF INNER UG PROXIMAL TRENCH CUTTER EJF

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4gr (0.90 ct) 5gr (1.2 ct) 6gr (1.4 ct) 8gr (1.8 ct) 10gr (2.5 ct) 3ct



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+1 ( 0.02 ct) to +5 (0.049 ct) +7 (0.12 ct) to 3gr (0.66 ct)

STONES PER 3,500 TONNES vs DIAMOND SIZE CLASS GROUPS


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Diamond Results STAR UG LDD & Trench Cutter

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4gr (0.90 ct) to 10gr (2.50 ct) 3ct to 15ct

STONES PER 3,500 TONNES vs DIAMOND SIZE CLASS GROUPS


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Diamond Results STAR UG LDD & Trench Cutter

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DIAMOND SIZE CLASS

STONES PER 3,500 TONNES VS SIZE CLASS, DTC STONE SIZE FREQUENCY PLOT

STAR UG EJF STAR LDD EJF INNER UG PROXIMAL TRENCH CUTTER EJF

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Diamond Typing Results STAR UG & Trench Cutter

STAR TRENCH CUTTER EJF SAMPLESDiamonds Typed +11 3GR 4GR 5GR 6GR 8GR 10GR 3CT 4CT 5CT 6CT TOTAL

Total 104 13 16 0 4 6 0 3 0 0 1 324

TYPE II 45 3 3 0 1 1 0 0 0 0 1 98

% TYPE II 43.3 23.1 18.8 0.0 25.0 16.7 0.0 0.0 0.0 0.0 100.0 30.2

STAR UNDERGROUND EJF SAMPLESDiamonds Typed +11 3GR 4GR 5GR 6GR 8GR 10GR 3CT 4CT 5CT 6CT TOTAL

Total 2608 200 200 162 189 158 39 71 32 18 12 3689

TYPE II 739 35 52 26 47 38 11 15 8 6 1 978

% TYPE II 28.3 17.5 26.0 16.0 24.9 24.1 28.2 21.1 25.0 33.3 8.3 26.5

• Diamond typing for the first three trench parcels has an anomalous number of Type IIa Diamonds in the +11 diamond size fraction

• This requires further investigation to assess if this is a result of diamond breakage

• Star Diamond personnel were not provided the opportunity to review these typed diamonds prior to their shipment to Antwerp

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Conclusions: Star UG, LDD & Trench Cutter• There is an under recovery of larger stones (0.90 carats and above) compared to the underground bulk

sample and the 48 inch LDD program

• There is a better recovery of the small diamonds in the 0.02 to 0.05 carat range. This adds to the gradeof each trench cutter hole compared to the grades of the 48 inch LDD program. This recovery is due tothe efficient operation of the DMS cyclone for the limited size range of +1-6 millimetres

• The stone size frequency plot shows that the Trench Cutter has not outperformed (to date) the 48 inchLDD program. In fact it has underperformed in the important larger stone size classes above 0.9 carats

• Diamond typing for EJF diamonds from the first three trenches has an anomalous number of Type IIaDiamonds in the +11 diamond size fraction, this requires further investigation to assess if this is a resultof diamond breakage

• Diamond breakage analysis and typing must continue for all the EJF samples of the ten trench cutterholes

• All remaining +6mm samples must be crushed and processed before processing is deemed completed

• Audits of the DMS concentrate and float tails must also be completed before the processing is deemedcomplete

• A selection of large diamond (1 to 15 carats) spikes must be added to the primary feed bin of the BSPfor a number of samples to fully audit the potential for the plant for diamond recovery and breakage

Slide Number 1Star Trench and LDD HolesDiamond Results STAR UG, LDD & Trench CutterDiamond Results STAR UG, LDD & Trench CutterDiamond Results STAR UG, LDD & Trench CutterDiamond Results STAR UG, LDD & Trench CutterDiamond Results STAR UG, LDD & Trench CutterDiamond Results STAR UG LDD & Trench CutterDiamond Results STAR UG LDD & Trench CutterDiamond Typing Results STAR UG & Trench CutterConclusions: Star UG, LDD & Trench CutterSlide Number 12

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Star - Orion South Diamond Project & Fort à la Corne ......3 4 Diamond Results STAR UG, LDD & Trench Cutter 0 200 400 600 800 1000 1200 1400 1600 1800 +5 (0.049 ct) +7 (0.12 ct) +9