I originally put this together to help out a friend who was just starting to get into junior mining investing. Considering we’re in a commodities bull run, I figured it could also be useful for anyone who wants to actually read a press release and have some idea of what the drill results mean.
It’s not a deep technical breakdown, just the kind of stuff that helps you get a feel for whether a company’s drill results actually mean anything.
Why this matters
The whole reason junior miners drill is to prove that their project has enough metal in the ground, in the right place, and that it can actually be pulled out and sold at a profit. That’s what separates a story stock from something that could one day turn into a real asset.
If you can’t make sense of the results, it’s easy to get caught up in flashy numbers that don’t mean much. This isn’t about becoming an expert, just learning to filter the noise.
What does “g/t” mean?
“g/t” stands for grams per tonne. If a company reports “2.5 g/t gold,” it means they found 2.5 grams of gold in every tonne of rock drilled from that section.
Higher numbers mean richer rock, but context matters. In gold mining, 1 g/t might be considered strong for a large open-pit deposit, while underground projects often aim for 5 g/t or more. For other metals, like copper or silver, the scale is completely different.
What does “over X metres” mean?
This tells you how thick the mineralized zone is. “2.5 g/t over 10 metres” means that grade was consistent across a 10 metre stretch of drill core.
A good grade with almost no thickness will not move the needle. A thick section of rock with almost no grade will not excite anyone either. You want both, grade and width together.
Grade times width is what really matters
A result like “5 g/t over 2m” might sound great, but it is just a small hit. On the other hand, “1 g/t over 50m” could be far more valuable because it shows bulk tonnage potential.
This is where you think in terms of grade multiplied by width. Decent grade with meaningful thickness is what counts. One without the other usually does not matter much for the economics of a deposit.
Watch for grade smearing
Sometimes drill results look better on the surface than they really are. You might see something like “1.5 g/t over 50m,” but when you dig into the details, most of that stretch is low grade with only a small high-grade hit pulling the average higher. That is called grade smearing.
The better companies will break it down for you. For example, “1.5 g/t over 20m, including 10 g/t over 1m.” That kind of detail gives you a clearer picture of what is actually in the rock. If the breakdown is missing, it is fair to be skeptical.
Depth makes a big difference
A strong hit near surface is usually much more valuable than the same hit 500 metres underground. Shallow mineralization is cheaper to drill, easier to access, and far more likely to become a real mine. Companies can move a shallow deposit toward production faster because the costs are lower and the engineering is simpler.
Deeper hits are not worthless, but they are harder to make profitable. The further down you go, the more expensive it becomes to drill, build shafts, and move rock. For a deep deposit to make sense, the grades usually need to be much higher to offset those costs.
What makes a result actually “good”?
What counts as a good result depends on the type of project. For open pit mining, grades around 1 to 2 g/t gold can be considered strong, especially if they come over wide intervals. The economics of open pits are based on moving large volumes of rock cheaply, so lower grades can still work.
For underground projects, the bar is higher. You usually want to see grades above 5 g/t gold, and in many cases even higher, because underground mining is far more expensive. Narrow but very high-grade hits can still be valuable here.
There is no single magic number. The best way to judge is to compare new results to what the company has drilled before, or to look at deposits in the same region that have gone into production. Context is everything.
Where they drill matters
Not all drill holes are equal. Where the company chooses to drill can say a lot about the importance of the result.
Testing a new zone is often the most exciting because it shows discovery potential.
Expanding a past discovery can also add value by growing the known resource.
Infill drilling (filling gaps between old holes) is usually less exciting. It is necessary for resource estimates but rarely moves the stock on its own.
Big hits in new areas or meaningful step-outs from existing zones are the results that tend to push a story forward.
Not all metals are equal
This might seem obvious, but it trips people up. A number only matters when you know what metal it refers to.
For example:
5% zinc is not worth nearly the same as 5% copper.
5 g/t silver is far less valuable than 5 g/t gold.
Always check the metal before assuming the result is impressive. High numbers can still mean very little if the metal is low-value.
Final thoughts
I hope this helps you make a bit more sense of mining press releases. There are some great mining stocks out there right now, and being able to read the drill results for yourself can give you more confidence in what you’re investing in, or even just considering.
I get that for a lot of people this stuff can seem dry or boring. But if there’s money to be made in mining companies, taking the time to understand the basics is worth it. Even a little bit of knowledge can go a long way.
