- Analysis of 12 >0.3mm diamonds, recovered in 2021 from the Sequoia kimberlite complex shows 50% are nitrogen free type IIa diamonds
- This result adds to a number of lines of evidence that this kimberlite complex has the potential to carry >50ct gems, indicator mineral chemistry collaborates with this, along with the diamond size distribution and the diamond descriptions (all described as clear white).
- Further drill definition is underway, this work will aid plans for a future bulk sample to recover >1500ct of commercial stones.
May 17th, 2022 Vancouver, British Columbia – Arctic Star Exploration Corp. (“Arctic Star” or the “Company”) (TSXV: ADD) (Frankfurt: 82A2) (WKN: A2DFY5) (OTC: ASDZF) is pleased to announce that has received the results of a diamond type study based on twelve >0.3mm diameter diamonds retrieved by caustic fusion analysis of the Sequoia Kimberlite in 2021, on is Diagras diamond property, NT
The diamonds were studied at the Saskatchewan Research Council Diamond laboratory in Saskatoon, (an ISO/IEC 1705 Standard lab), using Fourier Transform Infrared (“FTIR”) Spectrometry. This type of spectrometry is used to determine the concentration and aggregation state of nitrogen within the diamonds. Diamonds are broadly divided into two types (I and II) based on the presence or absence of nitrogen impurities and further subdivided according to the arrangement of nitrogen atoms (isolated or aggregated) and the occurrence of boron impurities.
The results show that 50% of the diamonds are nitrogen free type IIa diamonds, 33% Type IaA, and 17% Type IaB. See Figure 1 showing a pie graph depicting the results. This is in contrast to the global distribution where it is estimated Type IaA dominates 96% and Type IIa diamonds only make up 2%.
Figure 1, Diamond Type distribution from Sequoia Kimberlite Caustic Fusion, Left, Estimated global distribution of these diamond types right.
Only a small number of active diamond mines regularly produce Type IIa diamonds with the most significant of these being Letseng-la-Terae (Letseng Mine) in the Kingdom of Lesotho and Karowe in Botswana. While Letseng is a low grade (1.5-3 cpht) kimberlite and Karowe 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. The Koloa pipe, part of the Ekati mining complex, 34 kilometers west of the Sequoia kimberlite complex is also known to contain these types of diamonds.
Type IIa diamonds contain no nitrogen or boron impurities and are frequently either top white colours (D, E, F, or G) or shades of brown. Many pink and brownish-pink diamonds are also Type IIa. Type IIa diamonds typically have an anhedral crystal shape and exhibit a range of elongated, distorted, or irregular morphologies. 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 726 carat Jonker to the 3,106 carat Cullinan. Interestingly inclusion studies find that the majority of these large stones have come from great depth.
On September 9th, 2021, Arctic Star released results of a study of the indicator minerals recovered from Sequoia, which were analyzed and interpreted by Chuck Fipke. Unusually abundant deeply sourced indicator minerals were reported ($DI indicators), and these are associated with >50ct large Type IIa diamonds from Leteseng, Karowe, and Ekati. This work thus predicted the presence of Type IIa diamonds, now confirmed by the FTIR.
Vice President of Exploration, Buddy Doyle, states: “The presence of a significant proportion of Type IIa diamonds in the Sequoia kimberlite complex caustic fusion samples is another line of evidence of the potential to host plus 50ct, high value diamonds, backed up by the collaborative indicator chemistry and the relatively coarse, low gradient diamond size distribution. Finally, SRC describes all the diamonds as clear and white, this is unusual as most kimberlites have a mix with a high percentage of boart.”
Buddy Doyle continued, “Arctic Star is currently drilling the Sequoia kimberlite to outline its size and shape and obtain more diamonds from caustic fusion to further constrain the grade, which current guidance puts at between 20cpht to 70cpht. The diamonds recovered by this year’s work will also be analyzed by FTIR. The information gained will allow the design of a >1500 carat bulk sample, which could be retrieved early 2023. Once we have the diamonds from the large sample we will be able to determine the average value per carat, essential in understanding the economic value of this complex.”
The reader is directed towards these references which were used to guide this news release.
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
Smith, E.M, Shirey, S.B., and Wang, (2017) The Very Deep Origin of the World’s Biggest Diamonds. Gems & Gemology Vol.53 No. 4 pp. 389-403
The Qualified Person for this news release is Buddy Doyle, AUSIMM, a Geologist with over 35 years of experience in diamond exploration, discovery, and evaluation. A Qualified Person under the provisions of the National Instrument 43-101.
About Arctic Star
Arctic Star is predominantly a diamond explorer, recently discovering 5 new kimberlites in the prolific Lac De Gras kimberlite field that supports 2 multi-billion dollar kimberlite mining complexes. The company also has a 958Ha Exploration permit containing several diamond-bearing kimberlites on its Timantti project, Kuusamo Finland. Arctic Star has optioned its Stein diamond project in Nunavut to GGL diamonds who plan work once Covid restrictions lift. The company continues to look for appropriate diamond opportunities elsewhere.
ON BEHALF OF THE BOARD OF DIRECTORS OF ARCTIC STAR EXPLORATION CORP.
Patrick Power, President & CEO
+1 (604) 218-8772
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Cautionary Statement Regarding “Forward-Looking” Information
This news release contains “forward-looking statements” including but not limited to statements with respect to Arctic Star’s plans, the estimation of a mineral resource and the success of exploration activities. In this release it is not certain if the kimberlite discovered will be economic or not as this depends on many factors. Forward-looking statements, while based on management’s best estimates and assumptions, are subject to risks and uncertainties that may cause actual results to be materially different from those expressed or implied by such forward-looking statements. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Factors that could affect our plans include our potential inability to raise funds as intended, and in such event we may require all funds raised, if any, to be used for working capital rather than the intended uses as outlined. Accordingly, readers should not place undue reliance on forward‐looking statements. Arctic Star undertakes no obligation or responsibility to update forward‐looking statements, except as required by law.