TSX: DIAM
SASKATOON, SK, May 31, 2022
/CNW/ - Star Diamond Corporation ("Star Diamond or the
Corporation") is pleased to announce that the Corporation has
completed a study into the abundance of Type IIa diamonds in the
Trench Cutter diamond parcels recovered from the Early Joli Fou
("EJF") geological units at the Star Kimberlite, as defined by the
Star Diamond geological model. The Star Kimberlite is located
within the Fort à la Corne diamond district of central
Saskatchewan, Canada (which
contains the Star - Orion South Diamond Project), on mineral
dispositions held in a joint venture with Rio Tinto Exploration
Canada Inc. ("Rio Tinto Canada"). During 2019, Rio Tinto Canada
completed the drilling of ten bulk sample holes (trenches) on the
Star Kimberlite using a Trench Cutter Sampling Rig. This study
confirms that unusually high proportions of Type IIa diamonds are
present in the Star Kimberlite. Of particular note is the
exceptionally high proportion of Type IIa diamonds in the larger
size fractions of the EJF of which 53 percent (8 of the 15) of the
largest stones, 4 carats and above are Type IIa. This study also
confirms and augments earlier studies conducted by Star Diamond of
Type IIa diamonds at Star (26.5 percent, +11 DTC (0.32 carats) and
above) (see News Releases dated June 09,
2010, March 4, 2019 and
May 02, 2022). Type IIa diamonds are
very rare and account for less than 2 percent of all natural rough
diamonds mined from kimberlites. Many high-value, top colour, large
specials (greater than 10.8 carats) are Type IIa diamonds, which
include all ten of the largest known rough diamonds recovered
worldwide.
The number and the percentage of Type IIa diamonds for the
Trench Cutter EJF samples are documented in the table below.
Star EJF Kimberlite
(Diamonds +9 DTC (0.18 carats) to 15 carats)
|
|
Number of Diamonds
Typed
|
Number of Type IIa
Diamonds
|
Percentage Type IIa
Diamonds
|
EJF +9 (0.18 ct)
& above
|
1,229
|
353
|
28.7
|
EJF +11 (0.32 ct)
& above
|
615
|
196
|
31.9
|
EJF 4 carat &
above
|
15
|
8
|
53.3
|
As can be seen from the table above, a significant number of
diamonds from the EJF geological units of the Star Kimberlite
have been analyzed and typed from the Trench Cutter program. The
diamonds analyzed represent a spectrum of diamond sizes from +9 DTC
(+0.18 carats) through all the large stones, up to diamonds of over
15 carats. The largest Type IIa diamond identified is a 16.96 carat
stone.
The twelve highest value stones from the EJF trench cutter
samples (3 carats and above) are listed in the table below. Of note
is that nine of these twelve highest value stones are Type IIa.
Diamond descriptions and valuations were completed by Mr.
Nelson Karun, Diamond Specialist,
Saskatchewan Research Council ("SRC") Diamond Services, on behalf
of Star Diamond:
Size
(carats)
|
Type
|
Colour
|
Model
|
Estimated Price
US$/Carat
|
Estimated Stone
Value US$
|
16.96
|
IIa
|
D
|
Makeable
|
6,500
|
110,240
|
7.29
|
IIa
|
D
|
Makeable
|
10,500
|
76,545
|
8.10
|
IIa
|
D
|
Makeable
|
6,406
|
51,889
|
6.36
|
IIa
|
D
|
Makeable
|
5,214
|
33,161
|
10.13
|
IIa
|
TLB1
|
Makeable
|
2,514
|
25,467
|
6.52
|
IIa
|
G
|
Makeable
|
1,894
|
12,349
|
6.28
|
IIa
|
TLB
|
Makeable
|
1,851
|
11,624
|
3.44
|
I
|
H
|
Sawable
|
3,286
|
11,304
|
3.30
|
I
|
I
|
Makeable
|
2,209
|
7,290
|
3.20
|
IIa
|
VTLB(H)2
|
Makeable
|
2,209
|
7,069
|
5.15
|
I
|
J
|
Makeable
|
1,183
|
6,092
|
4.08
|
IIa
|
D
|
Makeable
|
1,250
|
5,100
|
1 TLB: Top Light
Brown
|
2 VTLB: Very Top
Light Brown Polishes to the equivalent of H colour
|
The previous three highest value stones, recovered from the Star
and Orion South Kimberlites and valued at the SRC, are shown in the
table below.
Kimberlite
|
Size
(carats)
|
Type
|
Colour
|
Model
|
Estimated Price
US$/Carat
|
Estimated Stone
Value US$
|
Star LDD* Inner
EJF
|
11.96
|
IIa
|
D
|
Makeable
|
13,787
|
164,893
|
Orion South Underground
EJF
|
15.88
|
IIa
|
D/E
|
Makeable
|
6,040
|
95,915
|
Orion South LDD*
EJF
|
10.52
|
I
|
Fancy Light
Yellow
|
Makeable
|
8,300
|
87,316
|
* LDD = large diameter
drilling
|
Only a small number of active diamond mines regularly produce
Type IIa diamonds with the most important of these mines being
Letseng-la-Terae (Letseng Mine) in the Kingdom of Lesotho and more recently Karowe in
Botswana. While Letseng is a low
grade (1.5-3 cpht) kimberlite and Karowe has a grade of
approximately 15 cpht, they are probably the most prolific source
of large high-value Type IIa diamonds, which contribute to making
Letseng and Karowe highly economic deposits. Type IIa diamonds
contain no nitrogen or boron impurities and are frequently either
top white colours (D, E, F or G) or any shade of brown. Many pink
and brownish-pink diamonds are also Type IIa. Type IIa diamonds
usually have anhedral crystal shape and exhibit a range of
elongated, distorted, or irregular morphologies. Most importantly,
many high-value, top colour, large specials (greater than 10.8
carats) are Type IIa diamonds, which include all ten of the largest
known rough diamonds recovered worldwide, from the 890 carat
Incomparable to the 3,106 carat Cullinan.
Statistics on the proportions of Type IIa diamonds produced by
diamonds mines are not freely available. However, Bowen et al
(2009) published Type IIa FTIR measurements for 484 plus two carat
diamonds from the Letseng Diamond Mine. The Letseng Mine has a low
grade of some 1.5 to 3 cpht but is highly economic as a result of
its unusually high average diamond price (US$2,131 per carat in 2018). Letseng accounts for
some 30 percent of the world market share of diamonds greater than
25 carats and has produced some of the biggest gem quality diamonds
recovered in the past number of years including the 910 carat
Lesotho Legend, 603 carat Lesotho Promise, the 550 carat Letseng
Star, the 493 carat Letseng Legacy and the 478 carat Light of
Letseng. These are all Type IIa diamonds. The Karowe Mine of Lucara
Diamond Corp. has also produced some record Type IIa diamonds in
the past few years, notably 1,758 carat Sewelo, which is the second
largest gem diamond ever recovered, the 1,109 carat Lesedi La Rona, which is the third largest gem
diamond ever recovered and sold for US$53
million, and the 813 carat Constellation, which was sold for
the record price of US$63.1
million.
Fourier Transform Infrared ("FTIR") Spectrometry is used to
determine the concentration and aggregation state of nitrogen
within the diamonds using industry standard methods. All analyses
of nitrogen content and aggregation state were carried out at the
SRC high security diamond facility, with 24-hour video
surveillance. The SRC's Geoanalytical Laboratories is accredited to
the ISO/IEC 17025 standard by the Standards Council of Canada as a testing laboratory.
Senior Technical Advisor to Star Diamond, George Read, states: "The presence of a
significant proportion of Type IIa diamonds recovered in the Star
Kimberlite by the Trench Cutter greatly increases the potential for
the recovery of large (plus 100 carat), high-value diamonds from a
future mine. Analysis of the trench cutter diamond parcels
indicates a significant proportion of Type IIa diamonds, many of
which are top white in colour with high value. The presence of
high-value diamond groups (Type IIa) greatly strengthens the future
potential diamond pricing from the Star Kimberlite."
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 TSX Exchange
under the trading symbol "DIAM". Star Diamond holds, through a
joint venture arrangement with Rio Tinto Canada (a wholly-owned
subsidiary of Rio Tinto), a 25% interest in certain Fort à la Corne
kimberlites (including the Star – Orion South Diamond Project).
These properties 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. Rio Tinto refers to their Fort à la Corne
mineral properties as "Project FalCon". During 2018, Star Diamond
announced the positive results of an independent Preliminary
Economic Assessment (the "PEA") on the Project. The PEA (on a 100%
basis) estimated 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 to Star Diamond, 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.
References (Available on
Corporation's website)
Bowen, D.C. Ferraris, R.D. Palmer, C.E. and Ward, J.D.
(2009) On the unusual characteristics of the diamonds from
Letseng-la-Terae kimberlites, Lesotho. Lithos Vol. 112S pp.767 – 774.
Breeding, C.M. and Shigley, J.E. (2009) The "Type"
classification system of diamonds and its importance in gemology.
Gems & Gemology Vol. 45 No. 2 pp. 96 – 111
Caution Regarding Forward-Looking
Statements
This news release contains forward-looking statements as defined
by certain securities laws, including the "safe harbour" provisions
of Canadian securities legislation and the United States Private
Securities Litigation Reform Act of 1995. Forward-looking
information is often, but not always, identified by the use of
words such as "anticipate", "believe", "expect", "plan", "intend",
"forecast", "target", "project", "guidance", "may", "will",
"should", "could", "estimate", "predict" or similar words
suggesting future outcomes or language suggesting an outlook. In
particular, statements regarding the Corporation's future
operations, future exploration and development activities or other
development plans constitute forward-looking statements. By their
nature, statements referring to mineral reserves, mineral
resources, PEA or TFFE constitute forward-looking statements.
Forward-looking statements contained or implied in this press
release include, but are not limited to, the potential proportion
of Type IIa diamonds in kimberlites located in the Fort à la Corne
diamond district of central Saskatchewan,
Canada (which includes the Star, Orion South, Orion
North and Taurus Kimberlites), diamond valuations and the
potential for the recovery of large high quality diamonds.
These forward-looking statements are based on the Corporation's
current beliefs as well as assumptions made by and
information currently available to it and involve inherent
risks and uncertainties, both general and specific. Risks exist
that forward-looking statements will not be achieved due to a
number of factors including, but not limited to, developments in
world diamond markets, changes in diamond prices, risks relating to
fluctuations in the Canadian dollar and other currencies relative
to the US dollar, changes in exploration, development or mining
plans due to exploration results and changing budget priorities of
Rio Tinto Canada or Star Diamond, the impact of changes in the laws
and regulations regulating mining exploration, development,
closure, judicial or regulatory judgments and legal proceedings,
operational and infrastructure risks and the additional risks
described in Star Diamond's most recently filed Annual Information
Form, annual and interim MD&A.
Although the management of Star Diamond consider the assumptions
contained in forward-looking statements to be reasonable based on
information currently available to them, those assumptions may
prove to be incorrect. When making decisions with respect to Star
Diamond, investors and others should not place undue reliance on
these statements and should carefully consider the foregoing
factors and other uncertainties and potential events. Star Diamond
does not undertake any obligation to release publicly revisions to
any forward-looking statement to reflect events or circumstances
after the date of this release, or to reflect the occurrence of
unanticipated events, except as may be required under applicable
securities laws. Investors should not assume that any lack of
update to a previously issued forward-looking statement constitutes
a reaffirmation of that statement. Continued reliance on
forward-looking statements is at investors' own risk.
www.stardiamondcorp.com
SOURCE Star Diamond Corporation