Reserves and Resources

Mining area Terrace complex Bottom cut-off size Volume m3 Grade*ct/100m3 ValueUSD/ct
Saxendrift Brakfontein Hill (“BHC”)
B1 terrace
5mm 3,230,000 0.36 2,800
Saxendrift Hill Saxendrift Hill (“SHC”)
B2 terrace
5mm 392,400 0.37 2,500
Saxendrift Extension Saxendrift River (“SRC”)
C3 terrace
5mm 1,529,500 0.54 2,000
Total Indicated Mineral Resource 5,151,900 0.42 2,500
Saxendrift Brakfontein Hill (“BHC’)
B1 terrace
5mm 379,000 0.40 2,800
Saxendrift Hill Saxendrift Hill (“SHC’)
B2 terrace
5mm 820,000 0.40 2,500
Saxendrift Extension Saxendrift River (“SRC’)
C3 terrace
5mm 2,034,000 0.50 2,000
Kwartelspan Rooikoppie Kwartelspan Complex (“KPC’) 5mm 301,000 0.60 2,500
Total Indicated Mineral Resource 3,534,000  0.5 2,200


*Although the effective bcos going forward may be adjusted upward to 6mm, the average diamond values or grades will not be adjusted in order to account for the number of -6mm material that will still be recovered.

Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

Probable Mineral Reserves estimated for the Saxendrift Mine (as at 28 February, 2015)

Terrace Complex Mining Block Volume (m³) Grade* (Ct/100m³) Carats Value* (USD/ct)
Brakfontein Hill (“BHC”) B1 terrace Block M10 31,500 0.36 113.40 2,700
Block M12 44,900 0.44 197.56 2,300
Block N14 56,500 0.45 254.25 3,000
R15 Ext 54,400 0.36 195.84 2,800
Total Probable Reserve 187,300  0.41 761.05 2,700

* Bcos = 5mm

Inferred Mineral Resources on Niewejaarskraal Project (as at 28 February, 2015)

Terrace Complex Resource Block Geological Domain Volume (m³) Grade* (Ct/100m³) Value* (USD/ct)
A Terrace Block 1 BIF-rich brown gravels 6,286,000 0.5 1,850
Block 2 BIF-poor brown gravels 3,420,000 0.3 1,850
Colluvial gravels 1,820,000 0.5 1,850
Total Probable Reserve 11,524,000 0.4 1,850

* Bcos = 6mm
* Both grade and diamond value of total Inferred Mineral Resource is a weighted average
* The diamond value is a 2-year trailing average
* All values/grades are rounded off to reflect the low level of confidence in the estimate.

Inferred Mineral Resources on Remhoogte Project (as at 06 February, 2015)

Terrace Complex Resource Block Volume (m³) Grade* (Ct/100m³) Value* (USD/ct)
Remhoogte Remhoogte/HolslootRooikoppie gravel 7,056,000 0.9 2,900
Total Probable Reserve 7,056,000 0.9 2,900

* Bcos = 5mm

Resource estimation on Wouterspan (as at 28 February, 2013)

Terrace Complex Resource Classification Volume (m³) Grade* (Ct/100m³) Value* (USD/ct)
Wouterspan Indicated Resource 5,025,500 0.64 2,400
Inferred Resource 37,774,000 0.64 2,400

* Bcos = 5mm



# Due to a lack of reliable data on SHC, the 5mm bottom cut-off size (bcos) values are not included at Indicated Mineral Resource classification.

Diamond values (under “Values”) for BHC, SHC, KPC and Niewejaarskraal are based on a two-year moving average (from +10,000cts from the BHC terrace on the Saxendrift Mine at a 5mm bcos).

Diamond values for SRC are based on the 5mm bcos sales data for FY2013 only.

Diamond values for Wouterspan are based on extrapolation of FY2011 data at 5mm bcos.

Tirisano data is at 2 February 2012.

Resource and Reserve estimates completed by Rockwell’s Group Technical Manager, GA Norton, (PrSciNat), a Qualified Person who is not independent of the Company and reviewed by TR Marshall, PhD (PrSciNat), an independent Qualified Person.

Note: The Indicated Mineral Resources on the BHC terrace of the Saxendrift mine are inclusive of the Mineral Reserves.
Download the PDF here



Acquisitional Projects: On January 6, 2015, Rockwell announced that it had reached an agreement to acquire the Remhoogte/Holsloot Project, and released a Technical Report on March 9, 2015. To download the Technical Report:

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Technical Report on the Remhoogte/Holsloot Alluvial Diamond Project