What is Comet?

​​

Comet is a mass balance calculation program developed jointly with Fleet Space Technologies. It estimates quantitative mineralogy directly from 4 acid digest ICP analyses.

​

Why do we log mineralogy?

Every hydrothermal mineral deposit on the planet is geochemically zoned. Metals precipitate from hydrothermal fluid when there is a change in pH +/- temperature +/- redox. The evolving fluid composition also causes sequential changes to gangue mineralogy along the fluid flow path. Mapping and understanding the spatial variability of mineralogy from your drill holes is an important part of exploration.

Once you have found an orebody, understanding mineralogy is even more important at the mining stage. Gangue mineralogy will vary within an orebody. These variations influence drill and blast, crushing and grinding costs and rates, flotation characteristics, mill recoveries and net acid production from waste rock. All of this variability should be tested and quantified and built into the resource model.  

​

What are the options for modelling mineralogy?

Every company begins with visual logging of drill core and RC chips. It is impossible to identify all the significant gangue minerals and log them in a quantitative manner. That has led to the development of a variety of scanning techniques. Every mineralogical measurement system requires collecting another set of instrumental data from the drill core above and beyond assay data. In the case of core scanners, this requires mobilizing a mobile laboratory to site or transporting the core to a lab. This adds significant time and cost. SWIR instruments are great for picking low temperature phyllosilicates, but they do not measure quartz or feldspars, and SWIR data is not quantitative. TIR gives a better approximation of total minerals, but it is still expensive, semi quantitative, and dependent on having reliable mineral libraries.

qXRD, QEMSCAN and MLA are the gold standards, but they are so expensive that they can only be performed on a few selected samples.

​

Advantages of Comet

Comet fills a niche space between visual logging and methods that require re-analysis of core with a second instrumental system. Running the calculation on existing assay data makes it fast and cost-effective. The calculation can be run as soon as your assays are returned from the laboratory. It gives a mineral estimate on every sample where you have a 4 acid digest analysis, so it can be used to generate a data-dense mineralogy model for an entire deposit. It is an estimation method, but it will create well defined mineralogical domains that honour the assay results.

​​