NAGsters The Australian Institute of Geoscientists in its Best...

NAGsters
The Australian Institute of Geoscientists in its Best Practice Guidance, seems to feel visual estimates are no substitute for laboratory analysis. This would indicate that the best course of action is to wait until all samples have been analysed and double checked.

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https://www.herbertsmithfreehills.c...-of-mineralisation-to-report-or-not-to-report


An extract:

AIG'S BEST PRACTICE GUIDANCE
AIG notes in its guidance that it has received correspondence from members regarding the description and reporting of sulphide mineralisation in drilling samples. This correspondence relates to sulphide intersections being reported, prior to an assay being prepared, without any attempt to describe the nature of sulphide mineral occurrence, identify the minerals observed, or estimate the abundances of any sulphide minerals observed.

The AIG go on to state that estimation of the proportions of mineral species present in a sample, where individual grains or crystals are visible in hand specimen, is considered to be a skill in which geologists may be readily and meaningfully trained and work that may be guided by published resource materials.

They note that estimates by experienced, competent geoscientists are considered to be reliable and reproducible semi-quantitative estimates of the abundance of minerals present in a sample.

The AIG guidance does warn that visual estimates of sulphide mineral abundance should, however, never be considered a proxy or substitute for laboratory analyses where metal concentrations or grades are the factor of principal economic interest. In addition, visual estimates also potentially provide no information regarding potential impurities or deleterious physical properties relevant to valuations of some mineral commodities such as graphite and many industrial minerals.

The guidance states that reporting of visual estimates should be accompanied by an indication of when more substantive and reliable data in the form of laboratory analyses will be available.

The AIG guidance notes that any disclosure must comply with the underlying transparency and materiality principles of the Australasian Code for Reporting of Exploration Results, Minerals Resources and Ore Reserves 2012 Edition (JORC Code).


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Nanu