Drilling Results – How Can You Determine if a Mining Company’s Drill Results are of Low, Medium or High Grade

Drilling results for base metals are typically reported in percentage per tonne (%), while precious metals are reported in grams per tonne (g/t). As an investor, it’s crucial to understand if a drill result indicates low-, medium-, or high-grade mineralization, as this can provide insight into the potential financial outcomes of the deposit.

After analyzing and interpreting various drill reports to differentiate between low-, medium-, and high-grade mineralization, I have summarized my findings in the following table:

Low Grade, Medium Grade and High Grade Mineralization

ⓘ If on a mobile device, swipe the table to see all data points.
MineralizationSymbolLow GradeMedium GradeHigh Grade
Base MetalsCobaltColess than 1%1% – 2%over 2%
CopperCuless than 0.5%0.5% – 1.5%over 1.5%
Iron OreFeless than 25%25% – 35%over 35%
LeadPbless than 2.5%2.5% – 10%over 10%
Molybdenum1Moless than 0.15%0.15% – 0.5%over 0.5%
NickelNiless than 1%1% – 2%over 2%
ZincZnless than 2.5%2.5% – 10%over 10%
EnergyUranium2U3O8less than 0.15%0.15% – 0.40%over 0.40%
FertilizersPhosphate RockP2O5less than 25%25% – 30%over 30%
PotashK2Oless than 20%20% – 25%over 25%
Precious MetalsGoldAuless than 1.5 g/t1.5 g/t – 5 g/tover 5 g/t
PalladiumPdless than 1.5 g/t1.5 g/t – 5 g/tover 5 g/t
PlatinumPtless than 1 g/t1 g/t – 2.5 g/tover 2.5 g/t
SilverAgless than 10 g/t10 g/t – 50 g/tover 50 g/t

Comparing Drill Results

It’s important to note that grade alone isn’t the only factor to consider, as many profitable mining operations worldwide are extracting low- to medium-grade ore. Instead of solely focusing on the grade, it’s better to use gram-meters when comparing drill results from different companies. For example:

  • Company ABC reports drill results: 1 meter, containing 250 g/t Gold = 250 gram-meters
  • Company XYZ reports drill results: 50 meters, containing 5 g/t Gold = 250 gram-meters

As shown above, both companies report the same amount of gram-meters. To determine which project would be the better investment, you’ll need to consider mining costs, break-even analysis, and metal value. Comparing these factors can help you draw your own conclusions about each project’s potential. To learn more about mining costs, break even analysis, and metal value, I recommend reading the relevant pages by clicking the provided links.

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