KIM Report

Different Types of Diamonds at Fort à la Corne

Posted by David

Early last month, Shore Gold (SGF) announced that a high proportion (26%) of diamonds >2.7 c retrieved from the underground bulk sample at its 100% owned Star kimberlite in Saskatchewan are type IIa. This is a category of diamond that is typical of many “large special” diamonds >10.8 carats in size.

Diamond Types

In terms of impurities in their crystal structure, diamond can substitute nitrogen (N), boron (B), and/or hydrogen (H) for carbon. Nitrogen is the most abundant and well-studied impurity and can range from concentrations of 0 to >10,000 ppm (~1%). Diamonds with significant nitrogen (>10 ppm) are termed Type I and those without are Type II. N-bearing diamonds are further categorized into those where the substituting N is organized as single atoms (Type Ib) or as aggregates of more than one atom (Type Ia). These aggregates are classified into paired N atoms (Type IaA) or quartets (Type IaB), or a mix of both (Type IaAB).

Diamonds that are relatively free of N are Type II. Those with no N and some B are Type IIb. Type IIa diamonds are more common and have no N or B. Type Ib and IIb diamonds are relatively rare. Type Ia diamonds are the most common.

How Diamond Types Are Determined

How impurities such as nitrogen are arranged in a diamond can be determined in a non-destructive manner using Fourier-transform infra-Red (FTIR) spectroscopy. Simply, light of a lower energy than visible light (infra-red) is shone through the diamond. By measuring the exact amount of light of a given energy that comes out the other side of the diamond (i.e. how much light is absorbed), it is possible to learn things about the diamond’s molecular structure. For example, how much nitrogen is in the diamond, and if it is in atomic pairs, or quartets. Fourier-transform is a mathematical and instrumental technique applied to infrared spectrometry to speed up analyses.

Issues With The Report’s Interpretation

In their news release, SGF refers to the Letšeng-la-Terae (Letšeng) mine in Lesotho (operated by Gem Diamonds, LSE-GEMD). This mine is considered quite unique as its low grade – <0.04 c/t, but has diamonds impressive quality and size. Average diamond value for this mine is >US$2000/c. This means a revenue of ~$80/t (2008 values).

However, the report’s suggestion that Type IIa equates to higher value stones cannot be considered absolute fact. This is because the mine they are comparing their diamonds to – Letšeng, is an anomaly in terms of its diamond population. While it is possible that with further valuation of parcels for SGF pipes a higher valuation could be realized, the current one is only about 10% (~$225/c) of Letšeng’s.

The diamonds shown by SGF in the full report (see above image for an example)- while large, are typically yellow-brown and some appear to contain large inclusions (internal cracks or non-diamond minerals). The report goes on to compare Letšeng and Star diamonds in terms of size class and % Type IIa. While Letšeng does show a marked increase in % Type IIa with increasing size, Star shows only a marginal increase, if at all.

The FTIR report commissioned by SGF also makes an error when referring to the trend of increasing percentage of Type IIa diamonds with increasing carat size for Star as comparable to that of Letšeng. The trends for each pipe are in fact rather different. Letšeng shows a significant increase of the proportion of Type IIa diamonds with size, whereas Star shows only a marginal increase (see plot below).

The SGF report states that the above figure “shows explicity that the abundance of Type II diamonds increases with increasing diamond size.” This statement is misleading as it is really only true for Letšeng diamonds. The academic study on Letšeng diamonds that SGF references for this report was based on less than 500 diamond samples (large stones of value being hard to obtain even for non-destructive studies). This relatively small number means that care must be taken when applying this study on a small number of diamonds from one kimberlite to the entire potential production of another. Granted, not that many large diamonds have been made available for such studies, but such over-reaching statements should not be made.

While the results of the report are interesting, and parallels can be made with the academic paper on Letšeng, there does not appear to be much evidence at this point for increased financial prospects of the Star project in terms of diamond type. Star still has one tenth the average diamond valuation of Letšeng without having close to ten times the grade. Though this does not in any way forestall a diamond mine in Saskatchewan, far better numbers have to come out of the Fort à la Corne area kimberlites for it to approach the level of Letšeng.

Disclaimer: The author does not hold shares of any company mentioned in this article. Relevant comments are welcome and encouraged. Spam comments will be deleted. This article is based on the opinions and experience of the author. Please conduct due diligence when investing. ©KIM Report 2010 www.kimreport.com

Kimberlites and Diamonds of Western Canada

Posted by David

This year’s GeoCanada conference and related workshops saw some attention to diamonds and kimberlites. Specifically those located in the western Canadian sedimentary basin (WCSB), covering Alberta and Saskatchewan.

The two main kimberlite clusters in this region are the well-known Fort a la Corne (FalC), and the lesser known Buffalo Head Hills (BHH) occurrences. The former cluster is in Saskatchewan and has been the focus of a major JV between Shore Gold (operator) and Newmont, the background of which was discussed in previous KIM Report posts. On the technical aspect of things, Shore Gold has done a lot of work in characterizing the complex structure of their two most economic kimberlite pipes: Orion South and Star (both are ~100 Ma). These pipes are composed of multiple units each formed during a separate volcanic eruption millions of years ago on the margins of an ancient shallow inland sea that covered most of what is today called the Great Plains. There are at least five  main units: Pense, Viking, Early Joli Fou, Late Joli Fou, and Cantuar (see the 3D model of the Star kimberlite below: different colours represent different petrological units). These units each erupted at a different time over many thousand of years, and differ in petrology, diamond grade and diamond size distribution. To further complicate things, these eruptions occurred over a timespan during which the inland sea was alternately expanding and contracting. The effect of these sedimentary processes (e.g. erosion, transportation, deposition) on the erupted kimberlite material led to the concentration of diamonds in some rock units and the removal of diamonds from others.

The other less-studied cluster is the ~65-85 Ma BHH in Alberta. Both barren and diamond-bearing pipes occur, also with variable geology and diamond grades as with the FalC pipes, although the extent of the complexity is unknown. The highest grade pulled from a BHH sample so far is close to 0.9 c/t (K252). Most of the pipes are a JV between Canterra Minerals Corporation (TSX.V-CTM; 28.5%, operator), Shore Gold (28.5%), and EnCana Corporation (43%). Shore Gold and Canterra each carry 50% of the operating costs. Canterra is the result of the business arrangement between Diamondex Resources Ltd. (TSX.V-DSP) and Triex Minerals Corporation (TSX.V-TKM) in 2009. Diamondex and Shore Gold bought their shares in a deal with Stornoway Diamond Corp. back in 2007. They later purchased another 12% from Burnstone Ventures Inc. (CNSX-BVE, formerly Pure Diamonds). A smaller subset of diamond-bearing pipes has been discovered by Grizzly Discoveries Inc. (TSX.V-GZD). These kimberlites: BE-02 and BE-03, are in the southeast region of the BHH cluster, previously thought to be barren. Grizzly also owns interest in a couple of much smaller diamond plays to the ENE in the Birch Mountains area of Alberta, as does Shear Minerals.

A couple of other companies have diamond interests in the WCSB: Vaaldiam Mining Inc. (TSX-VAA – Candle Lake, Saskatchewan) and Forest Gate Energy (TSX.V-FGE, formerly Forest Gate Resources – Fort a la Corne, Saskatchewan). However, activity on these properties has been fairly light (see map image of kimberlites in the WCSB below).

Both the BHH and FalC clusters were initially discovered by activities relating to energy exploration – petroleum and uranium, respectively. The BHH pipes were discovered by re-evaluating aeromagnetic survey maps that had classified the anomalies caused by the pipes to be well-heads for the oil fields that clutter the region. Some diamonds from these pipes have even been found to be coated with petroleum when recovered. The FalC cluster was found during aeromagnetic surveys. These pipes are located under 80-100 m of gravel, sand, and clay.

Though in comparison to other diamond mining regions (e.g. the Northwest Territories or the Otish Mountains in Quebec) current grade numbers are rather low, diamond valuations that do exist (only from FalC at this point) are higher than average for Canadian kimberlites. Access to infrastructure is also better, particularly when compared to Arctic kimberlites. This bolsters the revenue $/t kimberlite coming from those pipes. The main hurdle with this is the geological complexity of the FalC (and to a lesser extent BHH). Overcoming this problem has taken Shore Gold and the previous owners of the FalC pipes the better part of 20 years to overcome with exhaustive drilling and geophysics. The amount of detail given in recent reports indicates that their geology and diamond characteristics are becoming less vague, at least for the Orion South and Star bodies. Now having more information where and how rich the higher-grade zones are at Orion and Star, have allowed Shore Gold (and Newmont) to almost finalize their mine plan. Mr. George Read, Shore Gold’s senior VP exploration and development, confidently expects a full net profit after all costs and taxes of ~$25/t (CAN) ore from the project as it stands. The 50+ other kimberlite pipes remaining at FalC, along with those at BHH represent possible future resources for Shore Gold and its partners beyond the two currently gearing up for production.

On an ending note, Shore Gold reported re-valuation (April 2010) of the diamond parcels it had originally sent out and had valuated in March 2008. Price increases (in US$/c) since then are 10-20% higher for every parcel. What to keep in mind here is how the American dollar (what the revenues come in) fares against the Canadian dollar (what the costs come in). Over the past two years, the exchange rate has fluctuated from about $1 (US) buying $0.98 (CAN) to $1.30 (CAN). How much of that price increase is due to supply/demand and not currency adjustment is uncertain.

Disclaimer: The author holds shares of SWY, SRM, and FGE. Relevant comments are welcome and encouraged. Spam comments will be not posted and deleted. This article is based on the opinions and experience of the author. Please conduct due diligence when investing. ©KIM Report 2010 www.kimreport.com

Bye-Bye Dubai

Posted by David

Aftershocks

The recent plea from the Dubai sovereign wealth fund, Dubai World, for a moratorium on payments to their $59 billion (USD) debt underscores that there are still plenty of skeletons in the closet to be found as the world economy races and stalls back to recovery. Sometimes this engine even goes backwards for a bit in the face of surprising news such as this.

Is this revelation really so surprising? Perhaps in the particular details and that it involves a supposedly wealthy country backed by decades of high oil production revenues. Or at least it was before it invested a good bit of that money to finance the hyper-development of a previously sleepy Arabian emirate. However, it is not surprising that large negative developments continue to come to light as the financial systems recover and consolidate. It took many years of unchecked greed and financial short-sightedness to create the crisis (crises?) that started in 2007. It is only logical that it will be a few years until we are free of this baggage.

What does this mean for commodities? The “good times” are gone and many investors/developers now have to deal with an annoying factor known as “reality” when they are interpreting the market, supply/demand trends, and so forth.

This whole topic is too big for one article and it would be redundant, not to mention exhausting, to focus on an all-encompassing review of things as they stand and look to do so in the future. Following the news of Dubai World’s troubles made me think of all the discretionary luxury goods (haute couture, man-made islands shaped-like things, and particularly jewellery) that are disproportionately consumed by such a rather small population, and how that allegory can be expanded to the world at large.

Are those we previously thought to be ultra-rich truly immune to economic fluctuations? It really is a relative matter, but it appears that the 2007-2009 meltdown(s) has (have) even touched those we thought to be dependable for the consumption of commodities of limited practicality. Diamonds (and other gems) are perhaps the best example of such an item. They can be synthesized easily now for aesthetic and industrial purposes, leaving natural diamonds of no particular commercial use aside from vanity and symbolism.

However, it is the rarity, history, and symbolism/mystique surrounding natural diamonds that makes them so sought after, even in troubled economic times such as now.

This recent reprieve in the markets over the past six months has been accompanied by bursts of positive news releases from a previously lacklustre Canadian diamond exploration sector. This recovery was second to only that seen by rare earth metals in the past few months.

Peregrine First Out of the Gate

The major catalyst for this renewed interest in diamond properties in 2009 was the Chidliak discovery on Baffin Island. Although the most recent news from Peregrine (and JV partner BHP Billiton) was less than stellar compared to previous developments, the Chidliak-Qilaq project is the first diamondiferous kimberlite discovery in Canada in years to hold significant economic potential. PGD stock has relaxed from its surprising highs in September-October stable levels at well over $1. The nature of the Chidliak find was covered in an earlier article back in March. What is interesting in recent months is the lag time for the market to acknowledge this find: about six months since its first real publicity at a sparsely attended PDAC session on diamond exploration.

Shore Pushes Onwards

Two other major players in the Canadian diamond junior sector have seen stock jumps more closely tied to news releases. Shore Gold released its most recent NI 43-101 complaint report concerning the Orion South kimberlite body in the Fort a la Corne (FalC) JV project with Newmont in Saskatchewan (not to be confused with the adjacent Star property wholly owned by SGF). This technical report and resource estimate is lengthy at 108 pages, as it should be considering the complex geology found in the FalC pipe compared to some other Canadian kimberlites (e.g. Snap Lake, Lynx). The bulk of the geological characteristics of the FalC kimberlites were covered in an earlier KIM Report article. The main issues indicated with that article over a year ago was for SGF to up their average diamond valuations due to grades well below 1 ct/t (100 cpht), and to give a reasonable estimate of the total mining cost per ton. The proximity of local communities and their infrastructure (power, roads, etc.) will bring costs down well below those of Arctic projects. But by how much? P&E Mining Consultants do a very thorough job of considering all technical aspects of the most promising body of the 70+ in the FalC project.

SGF and NEM commissioned WWW International Diamond Consultants Ltd. to evaluate the diamonds recovered from underground and LDDH samples. 2320.2 c was priced at $199495 (US), or $86/c (using the March 11 2008 pricing). The most promising units of the Orion South kimberlite: EJF and P-2 had price ranges of $100-166/c and $91-123/c, respectively. Diamonds from other lithologies of Orion South have lower valuations. P&E optimistically use the high end values for their modelling of the resource. This is significantly lower than the $225/c valuation at Star, located 2.5 km to the SE. Grades range from 0.128-0.147c/t depending on the case used. Tonnage (minimum case) is 76.8 Mt indicated and 86.3 Mt inferred.

The mining plan for Orion South suggests an open pit. Slope of the pit wall would be 30º for the ore/waste rock and 18º for the overburden due to its unconsolidated nature.

Mining costs are hard to put together from just reading the report. It assumes that the exchange rate will be US$0.85/CAD$. Stripping costs for the overburden (glacial till) will be $1/t overburden, with mining, processing, and general/administrative costs pegged at $6.54/t kimberlite. Thus using the absolute minimum values SGF and NEM look to clear about $4/t (rough estimate for overburden clearance) from Orion. Though should aspects such as US-CAD exchange rates, rough diamond prices, and/or fuel prices strongly fluctuate, this number could go much higher or lower. The key assumption being made here -as with all deposits, is that the modelled resource accurately reflects the real resource in the ground closely enough that it remains economic. The major difficulty with the FalC kimberlites is that their petrological/lithological heterogeneity (i.e. changes in diamond grade throughout zones in the kimberlite body) is difficult to pin down. The overall low grade of the pipe and mediocre diamond valuation (compared to other pipes with grades <0.5c/t) leaves little room for mistakes, mistakes that SGF and NEM have spent years and millions of dollars to avoid.

At its conclusion the Orion South/Star project requires a further $4.5 million to bring things to the feasibility stage, not all that much compared to the aggregate amount spent on developing the FalC kimberlites since their discovery in the late 1980s.

Last, But Not Least

The second major junior in the Canadian sector is Stornoway. This has followed the trend set by Peregrine and then Shore Gold in a resurgent Canadian diamond exploration sector. First reporting 4x the original tonnage for the Renard-2 kimberlite property in early October and then expanding on that find this month by reporting revised numbers for entire Foxtrot (Renard, Lynx, and Hibou bodies) property (aka the Renard Diamond Project) that effectively triple the contained carats compared to estimates published last year. 23.0 Mc are indicated and 13.3 Mc are inferred with further upside as some bodies remain not fully studied. Grades at Renard-2 for indicated (1.03 c/t) and inferred (1.2 c/t) resources are up 27% and 39% respectively.

There is a bit of cloud to this silver lining though in that diamond valuations from Renard-2 and -3 are down 3% to US$117/c and for Lynx down 14% to $57/c (“Base Case” estimates). The NI 43-101 compliant technical report covering this release will be out in less than 45 days.

Considering these developments it is curious if any other diamond juniors will be lucky enough to come across some positive news in order to be next in line to capitalize on this new, but fragile, enthusiasm. With the tax-loss selling season approaching, that enthusiasm is fragile indeed.

Disclaimer: The author owns 4000 shares of SWY. This article is based on the personal opinions and experience of the author. Please conduct due diligence when investing. ©KIM Report 2009 www.kimreport.com

Bending Clifford’s Rule

Posted by David

In his famed 1966 paper, T.S. Clifford noted that diamond-bearing kimberlite pipes were always ones that intruded regions of ancient continental crust. To be more specific, these regions are Archean in age (>2.5 billion years old) and formed the tectonically stable cores of continents known as cratons. Thus “Clifford’s Rule” states that diamondiferous kimberlites occur in geologic regions that have been tectonically stable (i.e. cratons) since the Archean and that diamond exploration should focus on those areas.

 

However, over the past forty years these regions of high diamond potential have been thoroughly investigated for diamond deposits and a number of world class deposits have been found in this manner, such as those in the Canadian arctic. As time passes, there are fewer and fewer areas of apparent diamond potential that remain unexplored. Diamond prospectors must start looking in places that appear at first not to follow Clifford’s rule. More diamond discoveries are being made in regions where Archean craton is not obvious.

 

Attending this August’s 9^th International Kimberlite Conference, a prevalent theme was diamond exploration and discoveries in atypical areas falling outside of Clifford’s rule. For example, one presentation was regarding the nature of the Arygle mine, owned by Rio Tinto plc. Although situated in a Proterozoic (between 2.5 and 0.542 billion years old) mountain belt, Argyle has probably the highest diamond grade of all operating diamond mines. This presentation suggested the possibility of Archean mantle existing kilometers below the younger material at surface and thus providing the conditions optimal for diamond stability. Another example of developing properties in non-Archean areas is the diamondiferous Carolina kimberlite in Brazil. Located in the 1.8-1.2 billion year old Amazon craton, this kimberlite and others near it are being investigated by Sola Resource Corporation (TSX.V-SL). The characteristics of this kimberlite discovered thus far show no significant deviation from those of kimberlites situated in Archean cratons.

 

Regardless of how the current market environment is treating diamond stocks, the increasing core demand for diamonds has pushed diamond exploration to looking at areas previously considered to be at the fringes. Examples of significant discoveries in these areas include those mentioned above, plus Fort a la Corne, Saskatchewan; and Guaniamo, Venezuela.

 

The rising demand for diamonds has caused the small group of large companies who control the bulk of the rough supply (De Beers, Rio Tinto, BHP Billiton) to raise prices. As with any commodity, when price rises, new technology and new exploration philosophies are employed to discover deposits in previously unexplored areas.