One question that comes up in core logging is deceptively simple:
When core is heavily broken, how do you decide what length to record?
It sounds straightforward until you're standing in front of a core tray full of fragments, some of which fit together, some that don't, and others that could have broken during drilling, handling, or transport.
You still need to complete the log. The depth records need to make sense, and the recovery calculation needs to be defensible.
But forcing every fragment into a neat sequence doesn't necessarily make the data more accurate.
The problem with measuring broken core
Imagine a drill run with heavily fractured rock.
If you simply line up all the fragments and measure their combined length, you may overestimate the recovered core length. Gaps between pieces, incorrect ordering, and fragments from different positions can all affect the result.
On the other hand, leaving the core scattered in the tray and estimating its length by eye isn't a reliable solution either.
A sensible starting point is to reconstruct the core wherever possible.
Match natural fracture surfaces, preserve the original sequence, and measure along the core axis. If sections cannot be reliably reconstructed, document the uncertainty and follow the project's established procedure for handling those intervals.
The important point is to distinguish a measured length from an estimated one.
They aren't interchangeable, and the log should make that clear.
Not every broken piece tells the same story
This is where things get more complicated.
A core fragment may have broken along a natural joint or fracture. It may also have broken during drilling, extraction, transport, or handling.
Those possibilities can have very different implications for geological interpretation and rock mass assessment.
Unfortunately, the distinction isn't always obvious from the core alone.
Fresh-looking surfaces may provide clues, but appearance by itself is not definitive. The interpretation should consider the geological context, drilling records, handling history, and the logging procedures used on the project.
If the origin of a break is uncertain, it's better to record that uncertainty than to confidently label every break as natural or drilling-induced.
The same caution applies when interpreting RQD (Rock Quality Designation).
RQD is not simply the total length of recovered core divided by the drilled interval. It uses a defined method for measuring qualifying intact core pieces, commonly those at least 10 cm long, subject to the applicable standard and project procedure.
A run can have high core recovery but low RQD. One measurement cannot substitute for the other.
What about core loss?
Core loss creates another challenge.
If part of a run is missing, the missing interval should not be quietly filled in with an assumed length or treated as though the core had been recovered.
Check the drilling records, confirm the run boundaries, and document the discrepancy according to the project's procedure.
Also, be careful when comparing recovery figures between runs. The calculation method, depth references, and treatment of any residual core need to be consistent.
If the measurements don't reconcile, investigate the discrepancy before changing the numbers.
A clean-looking spreadsheet is not the same thing as reliable geological data.
A practical approach in the core shed
For heavily broken intervals, a few basic habits can prevent a lot of rework:
1.Reconstruct the core where the pieces can be matched reliably.
2.Keep the original sequence and run boundaries clear.
3.Measure along the core axis rather than estimating from a scattered pile.
4.Distinguish measured values from estimates and document uncertainty.
5.Record unexplained core loss instead of forcing the figures to agree.
6.Follow the project's procedure for recovery and RQD calculations.
These steps won't make every broken interval easy to interpret. Sometimes the evidence simply isn't good enough to reconstruct the original core with confidence.
That's a limitation worth recording, not something to hide.
How do you handle heavily broken core?
I'm interested in what actually works in the field.
When core is too fragmented to reconstruct confidently, do you have a standard method for recording recovered length and documenting uncertainty, or does the approach vary between projects and logging teams?
I'm especially interested in hard-rock exploration where natural fracturing and drilling-induced breaks can be difficult to distinguish.
Different teams may have different procedures, but the goal should be the same: produce a record that another geologist can understand, review, and defend later.
 

In traditional Sri Lankan gem mining, once we reach the Goda Illam, a shallow gem-bearing soil layer, we collect the soil in baskets and wash it using high-pressure water to separate the gemstones.

Finding a large stone during washing is always an exciting moment for both the workers and the mine owner.

We found this blue sapphire on the very first day of our new mining operation. It weighs approximately 8.5 carats in its rough form and has a clear blue colour, although it contains a small fracture.

Finding a sapphire like this on day one gives us hope that there are more gemstones waiting to be discovered in this land. Of course, the real potential of the deposit will become clearer as mining continues.

One of the most rewarding parts of gem mining is seeing the excitement shared by everyone when a beautiful stone finally appears.

Hello! I have a law background (worked in banking in Mauritius, in transaction advisory for a couple of years and I have an English law degree) and I am looking to explore my options in a career change. Has anyone here successfully pivoted? What kind of jobs do you have now and what are the hurdles did you face?

Thank you!!

(To note that I am British and Mauritian)

Tell me something i want to know

I’ve never worked mining before but I’m working a position I’ve done since highschool but never in a mine capacity

Wondering what kinds of ppe you guys are wearing, best work boots, etc any thing you might suggest

What’s the camp like and amenities ? Are things like bedsheets and towels provided ?

Any input you can offer I’m grateful for

Hello fellow miners, what has been your experience with Siton machinery?

The IEA says more than 2,500 GW of renewable, storage and large electricity demand projects are stalled in grid connection queues worldwide

That creates a timing question for mining demand forecasts

An announced project can support a forecast for future material consumption, but the construction schedule determines when those materials are actually needed

There are two effects worth separating

Delays to power plants and data centres can push some purchasing further out. Building the grid connections needed to unlock those projects creates its own demand for materials and equipment

The IEA estimates annual grid investment needs to rise by roughly 50% from around $400 billion today to meet electricity demand through 2030

It also says new grid infrastructure can take five to 15 years to plan, permit and complete

For miners planning expansions, that is a difficult timeline to match. Build too early and demand may arrive later than expected. Wait until every project is confirmed and new mine supply could be years behind

How do people working in the industry account for this? Are grid delays changing demand assumptions, or mainly shifting when customers expect delivery?

IEA:
https://www.iea.org/reports/electricity-2026/executive-summary

Anybody working at Seabee mine? How is it to work there?

Where do i find buyers

Hey Guys,

I'm Gowtham - An independent research working on field operation for mines in North America

I would love to do in-person field research across mines and talk with GIS specialist and geologist

Is there is any person i should talk to / you would recommend.

Feel free to suggest! the trip is fully funded by faculty

Hi everyone,

I’m looking to buy engineering blueprints and fabrication drawings for gold mining and mineral processing equipment.

I’m particularly interested in:

- Hammer mills

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I’m looking for detailed designs with dimensions, material specifications, and assembly drawings that can be used to manufacture the equipment.

If you’re an engineer, designer, or manufacturer who sells these plans, please comment or DM me with examples of your work and pricing.

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Hello all! I've been a truck and bus driver for 20 years, and I'm interested in starting a career driving the big mining trucks. Does anyone have any advice for getting into the industry as a middle aged man? I'm specifically looking at fly in, fly out jobs, as I don't want to have to relocate. Any advice?

Electromagnetic elutriation separators combine a controlled magnetic field with upward water flow to remove entrained gangue and low-grade locked particles from magnetite concentrates.

Key potential benefits:

• Higher concentrate grade through improved gangue rejection.
• Lower iron losses with suitable magnetic field and water-flow settings.
• More stable operation through automatic adjustment of water supply, concentrate discharge and excitation.
• Further cleaning of fine magnetite concentrates where additional upgrading is needed.

Performance depends on mineral liberation, feed size and operating conditions. Ore testing is essential to assess the balance between grade and recovery.

Anyone working with magnetic elutriation or considering it for their plant? Would love to hear your thoughts, questions, or experiences.

I am a Moroccan graduate who obtained a Master’s degree in Mining. My academic background is in geology, with interests in mineral exploration, geochemistry, mining environmental science. I also have some professional and internship experience in geology and am currently developing my career in this field.

My goal is to pursue a fully funded PhD in Europe, Canada, Australia, or the United States, preferably in a research area related to my Master’s degree.

My main question is What is the best way to find funded PhD positions in the same field?

Ratnapura is one of Sri Lanka’s most famous gemstone-producing regions. Besides the traditional alluvial gravel layers, gemstones can also be found in soil layers just 5–10 feet below the surface. These gem-bearing layers are locally known as “Goda Illam.”

Although many locations have already been mined, some areas still contain unexplored gem-bearing layers.

We recently started a new gem mining operation at one such location. In this video, I’m sharing the beginning of our journey to explore what lies beneath the ground.

I’ll share more updates as the mining progresses.

Was wondering if possibly anyone in here has been or is a state of Ohio mine inspector. Was looking at possibly doing it as a next step in my career but was wondering what the day to day typically looks like? How often are you away from home? Etc. Any input or opinions would be appreciated. Thanks!

How’s the bald hill site ? And is Low 200s about right 2/1 fixed plant electrician ?

Geologist here, office based and looking into more a career change with outdoor fieldwork, but want to know what’s it like driving at a mine site? Are the roads busy and is it common to have driving safety courses prior?