Star Diamond Announces Initial Results from Seventh Bulk Sample Trench of Star – Orion South Diamond Project

Star Diamond Announces Initial Results from Seventh Bulk Sample Trench of Star – Orion South Diamond Project

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by ahnationtalk on December 1, 2020129 Views


SASKATOON, Saskatchewan, December 1, 2020 – Star Diamond Corporation (“Star Diamond” or the “Corporation”) today announced that a total of 2,755 diamonds weighing 178.98 carats have been recovered to date from the seventh (19FALCT005) bulk sample trench excavated on the Star Kimberlite by Rio Tinto Exploration Canada Inc. (“Rio Tinto Canada”) in 2019.

“We are pleased by the recovery of two larger 16.96 and 6.35 carat D colour Type IIa diamonds from Rio Tinto Canada’s seventh trench,” said Ken MacNeill, President and CEO of Star Diamond. “Star Diamond’s own underground bulk sampling and large diameter drilling programs conducted between 2004 and 2009 previously recovered diamonds as large as 49.5 and 45.9 carats from the Star and Orion South Kimberlites, respectively. We have been disappointed by Rio Tinto Canada’s failure to date to recover larger diamonds, which we believe is a consequence of its unproven and inadequately tested extraction and/or diamond recovery methodologies causing undue diamond breakage. Nevertheless, the diamonds recovered from the seventh trench continue to highlight the excellent potential for the recovery of large high value diamonds from the Star Kimberlite.”

Mr. MacNeill continued, “We are also pleased that the initial results from the first seven reported trenches continue to validate the grades outlined in our Preliminary Economic Analysis that was based upon Star Diamond’s own prior underground bulk sampling and large diameter drilling programs.”

The breakdown of the kimberlite intercepted and diamonds recovered to date from trench 19FALCT005 is detailed in the table below.

Senior Technical Advisor, George Read, states: “The seventh trench (19FALCT005) has produced a total of 15 diamonds ranging from 1.10 carats to 16.96 carats. The six largest diamonds recovered to date from 19FALCT005 are 16.96, 8.05, 6.35, 3.72, 3.53 and 3.29 carats, respectively, and were all recovered from Early Joli Fou (“EJF”) kimberlite. The EJF is the dominant kimberlite unit within the Project in terms of ore volume and diamond grade. The 16.96 and 6.35 carat diamonds have been confirmed as being Type IIa using Fourier transform infrared spectrometry and their colour has also been confirmed as D. The recovery of these high colour, Type IIa diamonds in this bulk sample strengthens the expectation for recovery of large, high value diamonds in a future producing diamond mine. It is important to also note that the three large diamonds included in these trench results were all recovered from a soft EJF kimberlite breccia unit, from which kimberlite would have been more easily extracted with minimal mechanical attrition.”

Star Diamond has now publicly reported initial results from seven of the ten bulk sample trenches excavated by Rio Tinto Canada. Until critically important and comprehensive diamond breakage studies are completed, the processing, diamond recovery and reporting of all diamond results on the bulk sample trenches excavated by Rio Tinto Canada will not be complete.

Initial diamond stone and grade results for Trench 19FALCT005:

Kimberlite1 Kimberlite Drilled2 Carats3 Grade4 Stones per tonne Largest
Type Intercept (metres) Tonnes (+1 DTC) (cpht) (+1 DTC) (+1 DTC) Stone (ct)
LJF 112.00-148.70 321.79 2.443 0.759 124 0.39 0.051
EJF 148.70-230.30 882.05 176.536 20.01 2,631 2.98 16.961
Total 118.30 1,203.84 178.979 2,755


  1. Kimberlite Types: LJF: Late Joli Fou Kimberlite; EJF: Early Joli Fou Kimberlite. The LJF was not included in the Star Diamond PEA mineral resource estimate
  2. The excavated tonnes are calculated using theoretical trench volumes and core pilot hole dry densities provided by Rio Tinto Canada. These are equivalent to dry tonnes
  3. Commercial diamonds are defined as diamonds that will not pass through a +1 DTC screen, which has round apertures of 1.09 millimetres
  4. cpht: diamond grade in carats per hundred tonnes

Diamond results reported in this news release are based on diamond recovery processing conducted by SRC’s Geoanalytical Laboratories Diamond Services located in Saskatoon Saskatchewan. Primary recovery processing consisted of X-ray transmission (XRT) sorting, , magnetic separation and grease table recovery methods. SRC is an independent mineral processing facility which is accredited to the ISO/IEC 17025:2017 standard by the Standards Council of Canada as a testing laboratory for specific tests.

About Star Diamond Corporation

Star Diamond Corporation is a Canadian based corporation engaged in the acquisition, exploration and development of mineral properties. Shares of the Corporation trade on the Toronto Stock Exchange under the trading symbol “DIAM”. The Corporation’s Fort à la Corne kimberlites (including the Star – Orion South Diamond Project) are located in central Saskatchewan in close proximity to established infrastructure, including paved highways and the electrical power grid, which provide significant advantages for future mine development. During 2018, the Corporation announced the positive results of an independent Preliminary Economic Analysis (the “PEA”) on the Project. The PEA estimates that 66 million carats of diamonds could be recovered in a surface mine over a 38-year Project life, with a Net Present Value (“NPV”) (7%) of $2.0 billion after tax, an Internal Rate of Return (“IRR”) of 19% and an after-tax payback period of 3.4 years after the commencement of diamond production (see news release dated April 16, 2018).

All technical information in this press release has been prepared under the supervision of George Read, Senior Technical Advisor, a registered Professional Geoscientist in the Provinces of Saskatchewan and British Columbia and Mark Shimell, Project Manager, a registered Professional Geoscientist in the Province of Saskatchewan, who are the Corporation’s “Qualified Persons” under the definition of NI 43-101.

For further information: [email protected] or (306) 664-2202


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