11th Internaational Kimbberlite Conference Extendded Abstractt No. 11IKC--4536, 2017
Y Yellow and a whitte diamo onds from m Qilalu ugaq kim mberlitess: Two generatio g ons of diaamond growth g Anettaa Banas1, Thomas Stacchel2, Kareen V. Smit3, Ken Arm mstrong4 1
AP PEX Geoscience Ltd., Edmoonton, Canadaa,
[email protected] 2 University of Alberta, Eddmonton, Cannada, tstachel@ @ualberta.ca 3 Gemologicaal Institute of America, A New w York, USA,
[email protected] k u 4 North Arrrow Minerals Inc., Vancouvver, Canada, karmstrong@ k @northarrowminerals.com
uction Introdu A popullation of inteense yellow diamonds has been idenntified at thee Q1-4 kimbberlite on thee Naujaat (formerlly the Qilaluggaq) Project.. The Qilalug gaq Kimberlite Field is loocated near the t hamlet off Naujaat (Repulsee Bay), Nunnavut, Canadda. It consissts of 16 kim mberlites: 8 kimberlite pipes p and 8 laterally extensivve kimberlitee dykes. Thee kimberlitess were emplaaced at ca. 546 5 Ma (Kuppsch and Arrmstrong, 2013). T The Q1-4 kim mberlite, the largest (12.5 Ha) withinn the cluster,, is interpreteed as a multii-phased, complexx-shaped kim mberlite pipee. An Inferreed Mineral Resource R of 48.8 4 million tonnes at a grade of 53.6 cphht (total recoovery) contaaining 26.1 million caraats has been reported for Q1-4 (Kuppsch and Farrow, 2013). Backgroound In 2014,, a bulk sam mple was colllected from the t Q1-4 kim mberlite to provide p addittional inform mation on the diam mond contennt of the pipe and to esttablish whethher or not a population of yellow diamonds d recovereed in earlierr sampling persists p into the larger diamond d sizzes. Approxiimately 384 carats o diamondds larger thaan 1.1 mm (DTC+1) ( weere recovered from the 1,353.3 tonn ne bulk sam mple. The results ffrom the bulkk sample connfirmed thatt a populationn of yellow diamonds iss present at Q1-4 Q and that the yellow diam monds are preesent into thee grainer andd carater diam mond sizes (N North Arrow w, 2015a). a ely 9.0% by stone s count and a 21.5% by b carat weigght of the The yelllow diamondds comprise approximate total diaamond parceel. The yelloow diamondds display a range of huues, tones and a saturatioon levels, ranging from dark/iintense (oraangy) yellow w to very paale yellow (Figure 1). Dark/intensee yellow 3 by stonne count andd 6.5% by caarat weight of o the total paarcel. The prroportion diamondds make up 3.2% of yellow w diamonds increases, both b by stonee count and carat c weight, in the largeer size classees (North Arrow, 22015a). nd Samples Diamon A parcell of rough diiamonds conttaining 56 sttones
