Guide to Understanding Mineral Drilling, Assays and Good Grade for the Investor.

For those investing in the space or even a budding geologists, here is a basic guide on mineral drilling, assaying, and grade expectations for some important commodities.

Mining and exploration drilling results can be challenging to interpret for those not directly involved in the space.

So, I’ve put together a guide with basics on drilling, assaying, and how to assess good grades for the commodities that receive the spotlight in the news.

This perspective comes from my experience as a geologist in Australia. If you have any issues understanding the terms or need further explanations, please feel free to reach out. On the other side, for any geologists, this is elementary stuff and you probably won’t learn anything.

I consider myself a geologist with, generally, a broad base of industry knowledge (exploration focussed), with lots of room for improvement and certainly a master of nothing.

I also understand that this article might not be useful to some of you who subscribe, I cover a broad range of topics in this publication, just out of my interests.*

A caravan office (on the left) and sleeping in a swag next to the campfire in the middle of Outback Western Australia. Between this and a comfortable mine site office is where I spent most of my 20s.

It’s a beast (23 minutes read), so here is a glossary of what I’ve covered:

1: Introduction (above)

2: Drilling

• 2.1: Auger drilling

• 2.2: RAB/Aircore drilling

• 2.3: RC Drilling

• 2.4: Diamond Drilling (Geologist’s favourite)

• 2.5: Drilling summary

3: Understanding Assays

• 3.1: Fire Assay

• 3.2: 4-Acid Digest - ICP Analysis

• 3.3: pX-Ray Fluorescence (pXRF)

• 3.4: Assays summary

4: Defining good grade - what is the most important factor?

5: Grade guide for investors

• 5.1: Gold (Au) hard rock - open pit and underground

• 5.2: Copper (Cu) VMS and porphyry

• 5.3: Uranium (U) sedimentary and regolith (calcrete)

• 5.4: Lithium (Li) hard rock - magmatic and brine

• 5.5: Nickel (Ni) sulphides

• 5.6: Rare earths (TREO) hard rock - hydrothermal and clays

• 5.7: Tin (Sn) hard rock - hydrothermal

• 5.8: Silver (Ag) hard rock - hydrothermal

6: Summarized grade table for investors with what I’m bullish or bearish on.

7: Discussion and closing thoughts.

Additional content update:

• Starting this month, I’ll be writing a monthly newsletter article about Argentina. There's just too much happening here, and I find myself glued to the news now that the RIGI has passed the Senate and the people are finally getting what they voted for with Milei - a free market.