Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minuteWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallA drill result shows what was found in a particular sample interval; it does not prove that the surrounding deposit can be mined profitably. To judge a mining announcement, first identify the reporting rules and the type of disclosure, then examine the drill-hole context, sampling and assay details, resource confidence category, and assumptions used to estimate a resource or reserve.
First identify what the company is reporting
Mining announcements may describe exploration results, an exploration target, a Mineral Resource, or a Mineral Reserve. These are not interchangeable stages of evidence.
- Exploration results report observations such as drill assays. They are not a resource estimate and should not be presented as if they establish a deposit’s total tonnage and average grade.
- An exploration target is conceptual, not a Mineral Resource. The company should explain its uncertain nature, the basis for the target, exploration completed, and proposed further work.
- A Mineral Resource is an estimate based on geological evidence and sampling, with reasonable prospects for eventual economic extraction.
- A Mineral Reserve is the economically mineable part of an appropriate resource after applying modifying factors and completing the required level of study.
Check the issuer’s filing venue and the reporting framework named in the announcement or technical report. JORC applies in an Australasian context; U.S. registrants report under SEC Regulation S-K Subpart 1300; and Canadian disclosure is governed by NI 43-101 and related CIM definitions. Similar terminology does not make the rules identical.
The JORC publisher identifies the 2012 edition as the current edition and notes that JORC is incorporated into Australian and New Zealand exchange listing rules. The SEC’s small-entity compliance guide describes Subpart 1300, including dated, signed technical report summaries by qualified persons for material resource or reserve disclosures. In Canada, NI 43-101 requires scientific or technical disclosure on a material mineral project to be prepared by or under the supervision of a qualified person and specifies Form 43-101F1 for required technical reports.
#1 Best Overall
How to assess a drilling announcement
Start with the maps and cross-sections, not the largest grade in the headline. JORC requires enough information for a balanced judgement of exploration results, including relevant sampling, location, interval, analytical and contextual details. The JORC Code, 2012 Edition says that reporting isolated assays or drill holes without placing them in perspective is unacceptable.
Locate the holes and understand the intersection
Look for drill-hole collar locations and sections showing how the holes intersect the interpreted geology. Ask whether the reported interval represents a meaningful width through the mineralized zone. If true width is not stated, look for an appropriate qualification: the length drilled down a hole may not equal the deposit’s width across the ground.
Rank #2
Check how samples became assay results
Review the sample type, collection and recovery information, sample interval lengths, laboratory and analytical methods, and quality-control procedures. Then check how the company combined or weighted intervals. JORC calls for assay results to be reported with sample intervals, or for weighted average grades and the calculation method to be explained.
Look for omitted results and data limitations
A company need not publish every assay, but omissions should not prevent a balanced reading. Check whether the announcement explains relevant omitted holes or intersections and discloses material uncertainties, such as uncertain sample recovery or repeatability. These issues can affect how much confidence to place in reported grades.
What an assay and a reported interval do—and do not—tell you
A drill-hole assay is a result from a sample, not proof of a mineable deposit. A high grade in one interval does not, by itself, establish how much mineralization exists, whether it continues between holes, or whether it can be extracted economically. Its significance depends on its position in the geology, the interval’s width, the sampling and assay evidence, and the results of nearby holes.
Read the full set of disclosed intersections alongside the map, sections, and technical context. Do not treat a selected interval as representative of the whole project unless the company provides evidence supporting that interpretation. Nor should exploration results be converted into an implied resource total: a resource estimate requires geological interpretation, sampling information, and an assessment of reasonable prospects for eventual economic extraction.
How to interpret a Mineral Resource estimate
Under JORC, a Mineral Resource is a concentration or occurrence of material of economic interest whose location, quantity, grade, continuity, and other geological characteristics are estimated from geological evidence and sampling, with reasonable prospects for eventual economic extraction. As the Code puts it, “A Mineral Resource cannot be estimated in the absence of sampling information.”
Read the confidence category, not only the headline total
JORC resource categories, in ascending order of geological confidence, are Inferred, Indicated, and Measured. They describe confidence in the geological evidence and estimate; they are not grades for project success or probabilities of profit. A large total dominated by Inferred material is not directly comparable to the same total supported by higher-confidence categories.
Inspect the assumptions behind the estimate
The category label does not capture every uncertainty. In the technical report, look for the evidence and assumptions that shape the estimate, including drill spacing, geological and grade continuity, density data, estimation methods, cut-off assumptions, and unresolved limitations. JORC requires reasonable prospects for eventual economic extraction and calls for relevant technical and economic support for cut-off assumptions. Material uncertainties that could lead to under- or overstatement should be disclosed.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How a Mineral Reserve differs from a Mineral Resource
A Mineral Reserve is not simply a higher-confidence resource. It is the economically mineable part of an appropriate resource after applying modifying factors and completing the required level of study. Relevant factors may include mining, processing, metallurgy, infrastructure, economics, marketing, legal matters, and environmental considerations.
If a report gives both resources and reserves, check whether the resource figures are inclusive of or additional to the reserves. Do not add the two totals into a single number: under JORC, resources and reserves cannot be combined in that way.
How to compare two companies’ estimates
Compare the details on a like-for-like basis rather than ranking projects by headline tonnes, ounces, or grade.
- Framework and effective date: Note whether the estimate uses JORC, SEC S-K 1300, or NI 43-101, the report’s effective date, and whether newer information is available.
- Confidence mix: Compare the amounts in each category, not just the combined resource total.
- Geological support: Consider drill spacing, continuity, sampling and assay quality, and unresolved data issues.
- Estimate assumptions: Compare cut-off grade and, where disclosed, price, cost, recovery, and mining constraints.
- Study status: Separate exploration results and resource estimates from reserves supported by the required technical and economic work.
- Resource-reserve relationship: Check whether resources include reserves or are reported in addition to them.
A Canadian Securities Administrators review described a sample of 86 technical reports in its review of mineral resource estimate disclosures. That figure describes the review sample; it is not a measure of the error rate across all mining reports. See the CSA’s review announcement.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
