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.| Mineralization | Symbol | Low Grade | Medium Grade | High Grade | |
|---|---|---|---|---|---|
| Base Metals | Cobalt | Co | less than 1% | 1% – 2% | over 2% |
| Copper | Cu | less than 0.5% | 0.5% – 1.5% | over 1.5% | |
| Iron Ore | Fe | less than 25% | 25% – 35% | over 35% | |
| Lead | Pb | less than 2.5% | 2.5% – 10% | over 10% | |
| Molybdenum1 | Mo | less than 0.15% | 0.15% – 0.5% | over 0.5% | |
| Nickel | Ni | less than 1% | 1% – 2% | over 2% | |
| Zinc | Zn | less than 2.5% | 2.5% – 10% | over 10% | |
| Energy | Uranium2 | U3O8 | less than 0.15% | 0.15% – 0.40% | over 0.40% |
| Fertilizers | Phosphate Rock | P2O5 | less than 25% | 25% – 30% | over 30% |
| Potash | K2O | less than 20% | 20% – 25% | over 25% | |
| Precious Metals | Gold | Au | less than 1.5 g/t | 1.5 g/t – 5 g/t | over 5 g/t |
| Palladium | Pd | less than 1.5 g/t | 1.5 g/t – 5 g/t | over 5 g/t | |
| Platinum | Pt | less than 1 g/t | 1 g/t – 2.5 g/t | over 2.5 g/t | |
| Silver | Ag | less than 10 g/t | 10 g/t – 50 g/t | over 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.
