Learn · 8 guides

How to read mining announcements

Junior miners publish drill results, assays and resource estimates in a language of their own. These guides explain it, one piece at a time, with diagrams you can play with and the rules the companies have to follow.

Start with drill results Fly the investor flight simulator

Schematic cross-section: an angled drill hole from a collar at surface crosses a dipping mineralised vein from 85 m to 97 m down the hole Schematic, not to a real deposit mineralised vein PTD-014 collar 25 m50 m75 m125 m from 85 m 12 m @ 2.4 g/t Au incl. 3 m @ 7.1 g/t from 89 m next hole

The series

01How to read drill resultsWhat "12 m at 2.4 g/t from 85 m" means, and what to check in every drilling release.4 min read · start here02Grams per tonne and grade unitsg/t, ppm, %, oz/t and oxide grades like Li2O, with the conversions.2 min read03What is drill core?How diamond drilling cuts a core sample, how it is logged and assayed, and the core sizes.2 min read04Resources and reservesInferred, Indicated, Measured, Probable, Proved: what each category means.2 min read05The JORC CodeThe Australasian reporting code: Competent Persons, Table 1 and the categories.3 min read06NI 43-101Canada's disclosure rule: Qualified Persons, technical reports and what is in them.2 min read07Exploration drillingAircore, RC and diamond drilling, why holes are angled, and what a metre costs.4 min read08Junior mining companiesWhat juniors are, the stages from first hole to mine, and how they pay for it.2 min read

Try the interactive tools

Investor flight simulatorRead one real drill release in 3D, from the headline down to the intervalsInterval builderChange the cut-off and watch a headline result changeTrue widthDrag the angle of a hole through a veinGrade converterg/t, %, oz/t and oxides like Li2O, plus contained metalGrade-tonnage curveWhy a lower cut-off means more tonnes at a lower gradeCore trayHover the samples in a tray of illustrated coreVirtual core shedPull real core trays from seven South Australian holes and light up the assays

Handle real core

The virtual core shed holds real drill core from seven South Australian holes, among them the discovery holes of Carrapateena and Prominent Hill, scanned at the state core library. Pull a tray onto the logging bench, light up the assays and minerals along the core and build a headline intercept yourself.

Look up a word

The mining glossary explains over 300 terms in plain English, from assay and stope to true width, and the history of mining shows where many of them came from.

Then see real results in 3D

The investor flight simulator takes one real release from its headline down to the intervals in 3D, step by step. The latest drill results on the homepage open each release on its 3D model, and every project on the country guides marked 3D has one, with the holes, the intervals and the terrain.

These guides describe how companies report; they do not rate any company, project or result. Not investment advice.