​How to Find Uranium in Bancroft, Ontario: Radioactive Crystals, Geology & Rockhounding Guide

 

By Dark Star Crystal Mines — The Mineral Capital of Canada

Last Updated: 2026

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At Dark Star Crystal Mines Bancroft Ontario, tap into the geological systems that make rockhounding in Bancroft one of the most rewarding crystal collecting experiences in Canada. Bancroft is known worldwide as the Mineral Capital of Canada — a place where rare crystals, ancient geology, and human history intersect in spectacular fashion. Among Bancroft's most fascinating resources are it's uranium minerals, especially uranium-bearing species like uraninite (pitchblende crystals), uranothorite, and bright secondary uranium minerals that glow under UV light. At the Dark Star Crystal Mines you can pay to dig regular vein dyke crystals, but you might also find radioactive crystals.

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To truly understand why Bancroft hosts uranium at all, we need to place it in the bigger geological picture of how uranium forms and deposits globally — and why Bancroft is one of the very few places where uranium was mined from intrusive and pegmatitic systems rather than sedimentary basins.

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Table of Contents

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• Global Uranium Geology: How Uranium Forms Around the World

• Grenville Province Geology: Why Bancroft Hosts Uranium Deposits

• Why Bancroft, Ontario Became a Uranium Mining Hotspot

• Major Uranium & Radioactive Mines of the Bancroft Area

• Exploring the Historic Bicroft Uranium Mine (First-Hand Account)

• Life in Ontario’s Historic Uranium Mining Communities

• Living With Radiation in Old Bancroft Mining Towns

• Uranium & Radioactive Minerals Rockhounds Find in Bancroft

• How to Find Radioactive Crystals in Bancroft Safely & Legally

• What Uranium Teaches Rockhounds About Bancroft Pegmatites

• Unexpected Health Stories From Uranium Mining Life

• FAQ: Finding Uranium Minerals While Rockhounding in Bancroft

• About Michael Gordon – Dark Star Crystal Mines

 

Global Uranium Geology: How Uranium Forms Around the World

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Uranium occurs in many geological environments, but globally it is grouped into 15 major deposit types (IAEA classification). Most of the world’s uranium comes from three dominant styles:

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The World’s Main Uranium Deposits

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• Sandstone deposits – Kazakhstan, USA, Niger

• Unconformity-related deposits – Athabasca Basin (Saskatchewan), Australia

• Iron-oxide breccia complexes – Olympic Dam (Australia)

 

Intrusive & Granite-Related Uranium Deposits (Why Bancroft is Rare)

Bancroft belongs to this much rarer category, where uranium forms in:

• Granites

• Pegmatites

• Gneiss & skarn systems

• Structural vein zones

 

Global examples include:

• Rössing & Husab (Namibia)

• Kvanefjeld (Greenland)

• Palabora (South Africa)

• Bancroft, Ontario (Canada)

• Iron-oxide breccia complexes – Olympic Dam (Australia)

 

Why Bancroft Uranium is Globally Unique

 

Bancroft is one of the only places in the world where uranium was mined from pegmatite and intrusive granite systems, not sedimentary basins — making radioactive crystals in Ontario particularly unique.

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Uranium formed in Bancroft pegmatites rather than sedimentary basins because the region underwent intense high-grade metamorphism (Grenville orogeny) that mobilized uranium into late-stage magma fluids, allowing it to crystallize within granite pegmatites and granitic leucogranites. Unlike sedimentary basins that rely on low-temperature dissolution and deposition, the Bancroft deposits are magmatic or hydro-metamorphic, having been concentrated by heat and pressure rather than erosion and deposition.

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​Grenville Province Geology: Why Bancroft Hosts Uranium Deposits

 

​Below are several cases of where uranite and other radioactives can be found. The mines have long ago been lost and forgotten, but the Grenville Province geology remains. There are still granitic radioactive pegmatite dykes, as an Ontario rockhound you just have to find them.

 

⛏️ Madawaska Mine – Heart of the Uranium Rush

Geology:
Uranium in fractured gneiss and amphibolite near pegmatites.

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History:
Center of the uranium rush. Closed abruptly when the federal government stockpiled uranium and shut down producers. Discovered in 1952. Became Ontario’s largest uranium producer.

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⛏️ Bicroft Mine – Skarn & Rare Element System

Geology:
Uranium with apatite, amphibole, pyroxene in altered marble (skarn).

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History:
Famous for crystal associations and complex ground conditions. There were over 28 miles of side drift in the mine.

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⛏️ Dyno Mine – Pegmatites Uranium in Bancroft

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Geology:
Uraninite in coarse pegmatitic zones with feldspar and apatite.

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History:
Named for the heavy blasting needed. Small but high-grade. It had a mill on site, accommodation in the Dyno estates for Managers and a 525 meter shaft. 8.5 million tons was extracted but the tailings seemed less extensive than at the Bicroft Mine from which only half the amount of ore had been removed. Apparently a good deal of the material was dispersed at unrecorded locations within a 30 kilometer radius.

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"In the afternoon sun it was devilishly hot. Again there was the mysterious octagonal platforms that I'd seen at Bicroft. essentially just concrete pads held up by a forest of pillars. In the deadening silence it felt a little eerie. There was an aura of unspoken secrets guarded by a great multitude of basking snakes. One old-timer had whispered confidentially, "The only thing they was mining there was other people's pockets. They sold the shares you know" (not substantiated). (extract from Rockhound: An Experience of the North).

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⛏️ Silver Crater – Uranium, Silver and Cobalt Breccia Pipe

 

Geology:
Breccia pipe cutting marble and gneiss. Uranium with silver, cobalt, nickel.

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History:
Originally a silver mine in the 1800s—later produced uranium. It’s a short walk to get here and there is an adit that displays apatite and other large crystals. The mine is famous for its betafite crystals.

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⛏️ Cardiff – The Rockhound’s Classroom

 

Geology:
Famous pegmatites with feldspar, apatite, titanite, and accessory uranium minerals.

 

History:
Not a big uranium producer, but one of Ontario’s most important collecting and teaching sites. I found impressive plates of purple fluorite around here.

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Exploring the Historic Bicroft Uranium Mine (First-Hand Account)

 

I visited the unrehabilitated Bicroft mine site. I’d wandered into a field of lumber, graying with age and collapsed in piles . Looking for a head structure that may have indicated a shaft or adit entrance I couldn't see one. Today the site is cleared and both shafts are capped with concrete plates. A pipe protrudes to let the gasses vent.

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🌍 First-Hand Exploration of the Old Bicroft site

Surveyed from afar, concrete pilings from the Bicroft mine had suggested a Greek amphitheater. The shattered stumps of pillars were lined up like soldiers boots; roof and walls were gone and the floor was open to the sky. A massive structure at the far end of the amphitheater was topped by a raised octagonal platform.

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🌍 Yellow Cake, Fluorite and Uranophane at Bicroft

Most intriguing was an 80 foot metal silo, lying on its side with a hatchway leading into shadow. Rivets lined the hole like on the shell of a submarine. Inside murk hung like a polluted cloud and through the haze I could see a shaft with a propeller at its end.  Henry D. Later explained that the silo was one of the vessels in which yellow cake was mixed. I wish I’d known it then. The slurry had to be continually stirred or it would gel. If this brew solidified would someone have to scoop it out? Shortly after my camera stopped working and the film developed into darkened and smokey images (above, right).

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Huge crystals of fluorite and selenite had been extracted from the local rock and delicate yellow spines of uranophane were picked from this very location. (extract from Rockhound: an Experience of the North)

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Why Bancroft Ontario became a Uranium Mining Hotspot

 

Bancroft lies within the Grenville Province geology, a billion-year-old mountain belt formed during the Grenville Orogeny (1.0–1.3 billion years ago). These rocks were once deep inside an ancient mountain chain and later exposed by erosion and glaciation.

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What did the metamorphosism of this deep burial do for the area's uranium Deposition?

• Liberated uranium from source rocks

• Created fractures and fluid pathways

• Allowed uranium-rich fluids to move and crystallize in Bancroft area pegmatites

 

How Uranium crystallized in Grenville Rocks

Uranium travels in hot, oxygen-rich fluids and drops out when it hits reducing conditions, often near:

• Carbon-rich rocks like those found on the Dark Star Crystal Mines claims

• Iron minerals

• Sulfides

• Marble and skarn zones

 

In what type of rock formations do Bancroft area's radioactive minerals typically occur?

• Pegmatites

• Vein dykes

• Skarn systems

• Fractured gneiss & amphibolites

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Life in Ontario’s Historic Uranium Mining Communities

 

Aimsley’s story from the Bicroft Mine

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“Yeah, there was this time when the tank overflowed , guy come screaming past me for the showers. His clothes was already melted off his back”.

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I was sitting in Aimsley D’s kitchen with Aimsley himself, former electrical supervisor at the Bicroft Mine. He was well past 80, skeletal thin and softly spoken. A faded shirt hung limply from his sagging shoulders, his features fringed by a halo of wispy hair; the smell of toast from a late breakfast still hanging in the air.

As we talked Aimsley seemed lucid, but at times his words trailed off into silence. I often found myself speculating as to what he’d intended to say. Henry, Aimsley’s son, a big strapping fellow, sometimes finished the sentence for him.

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South of highway 121, built  in 1957 to connect highway 28 to the Bancroft area uranium mines - namely Bicroft Mine, Aimsley’s house sits atop a hill. With each passing year it looks increasingly neglected. Outside a stream of water pattered from the eaves trough and siding hung like sagging skin. An altered landscape was decaying all around.  The placement of roads, buildings and the very shape of contours had all been in relation to the needs of uranium extraction. Deep underground there are tunnels; some drop down in excess of 1500 feet. The abandoned mines sprawl out on many levels.

 

Though industry is gone it is only rockhounds who now scour the countryside.  Somewhere down below there are dark and yawning spaces that will sit untouched forever.

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In Aimsley’s kitchen the kettle had boiled for 20 minutes and nobody seemed to notice, we were absorbed by the telling of Aimsley’s bizarre and amazing life. He was entertaining and sometimes shocking and his narrative followed all sorts of unexpected twists and turns. The conversation turned to “yellow fudge”, It’s uranium concentrate with 70 – 90% uranium oxide. (U3O8) The cake comes from crushed and concentrated ore after it has been mixed with acid and leached.

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Living with Uranium in Ontario

 

Technically speaking yellow cake is no longer yellow. Higher calcining temperatures in new mills produce  a substance that is blackish – green; the base material from which fuel rods for reactors are made. I expressed interest at the change and Aimsley grinned. Like a hanged man he fatefully jerked his head back towards the door. “Oh I got some seeping from the barn beams”,  he said casually.Another Aimsley joke I wondered? Apparently not, the wood had come from the mines and according to him, in one of the many spills it had absorbed radioactive sludge.

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It was exactly as he’d said. The barn’s supporting structure was constructed from yellowing planks and upon them a granular encrustation had collected. It was yellow fudge (the yellow variety) and Henry discussed the toxic horror in an abstract sort of way, tracing the powdery smear along the grain with his fingers. Teetering at the door Aimsley smiled serenely. I wondered what monstrosities their chickens laid in that barn of silent menace. (Extract from Rockhound – An experience of the North)

 

Major Uranium and radioactive Mines of the Bancroft Area

 

By the early 1950s, prospectors recognized:

1. Bancroft already hosted rare-element pegmatites

2. Uraninite occurred in visible crystals

3. The geology was structurally perfect for uranium traps

 

This recognition of Bancroft as a potential uranium hot spot triggered what became known as the greatest uranium prospecting rush in the world.

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Initially the Ontario government had offered a reward of $25, 000 for any discovery of uranium in the Bancroft area. With a Geiger counter G.W. Burns found uranium in highly radioactive purple fluorite near Center Lake. The intense demand of the cold War pushed exploration to a higher level in the area, but by the 1960's it was mostly over with the US moving on to supplies in Saskatchewan.

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As H. Spence said at the World Nuclear Association’s 14th Annual Symposium:

“The roar from the great Canadian uranium rush was so great in 1953 that you could hardly hear the Geiger counters ticking.”

 

Between 1953–1956:

• Over 100 uranium claims were staked

• Multiple underground hard-rock mines opened

 

Uranium & Radioactive Minerals Rockhounds Find in Bancroft

 

Learning to recognize uraninite pitchblende crystals and fluorescent secondary minerals is an essential part of how to identify radioactive minerals in the field while rockhounding in Bancroft.

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Key Field Identification Methods

• Radiation Detection (Scintillometer/Geiger Counter): The primary, most reliable method. A device that "screams" or clicks rapidly when near radioactive rock is essential to distinguish uranium from similarly colored but non-radioactive minerals.

• Ultraviolet Light (UV Flashlight): Used at night or in shade, a UV light will cause many secondary uranium minerals to fluoresce with a "brilliant" or "neon" yellow-green glow.

• Visual Inspection (Color & Habit):

  • Primary (Uraninite/Pitchblende): Black, dark grey, brownish, or metallic-looking, often in dense, massive (SG - 9.0), or "grape-cluster" (botryoidal) forms.

  • Secondary (Weathering Products): Bright yellow, canary-yellow, or bright green coatings on fractures and in cavities.

 

 

 

 

 

 

 

 

 

 

Primary Uranium Minerals

• Uraninite (pitchblende)

• Uranothorite

• Brannerite

 

Secondary & Fluorescent Uranium Minerals

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• Autunite: Yellow to lemon-yellow, platy crystals. Highly fluorescent (bright green).

• Carnotite: Bright canary-yellow powdery coating or crusts. Common in sandstone.

• Uranophane: Lemon-yellow to orange-yellow, often fibrous or needle-like (acicular) crystals.

• Torbernite/Metatorbernite: Emerald green to grass-green tabular crystals. Often non-fluorescent or weakly fluorescent.

• Zippeite: Bright orange-yellow to yellow-brown, typically as crusts on oxidized rock. 

 

Many glow bright green under UV light, making radioactive crystals in Ontario especially exciting for collectors.

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How to Find Radioactive Crystals in Bancroft Safely & Legally

 

At Dark Star Crystal Mines Bancroft Ontario, we teach crystal collecting along with safety tips as part of every guided crystal dig in Bancroft and educational program.

 

🧭 Where are the best places to look for uranium minerals in Bancroft?

• Bancroft Pegmatite zones

• Skarn contacts in marble

• Fracture systems

• Old dumps and tailings (where permitted)

 

🛑 Radiation safety tips for rockhounds

• Never lick rocks 😅

• Don’t breathe dust

• Wash hands after handling or wear disposable gloves

• Store radioactive specimens in designated shielded locations

• Use a Geiger counter

• Minimize time spent near source, maximize distance from source

 

⚖️ Legal & Ethical Crystal Collecting in Ontario

• Never collect from protected or active mine sites

• Respect private land

• Follow Ontario Prospecting and Rockhounding regulations

• Practice ethical crystal mining in Canada​ as per basic rockhound considerations 

 

Unexpected Health Stories From Uranium Mining Life

 

Chatting with Aimsley you never knew what to think – was he messing with us or was he serious? He had this etherial quality like an angel. Angels only tell the truth! That morning he bought out a scrap book of clippings; its innards spilling like a gutted deer. Aimsley's theory was that some level of radiation was beneficial, “Bruce Evans who’d just died recently. In his 80s and not of radiation poisoning”. His index finger rose to emphasize the point. He’d packed yellow fudge into barrels for a job, lived a good long time that fellow did and he’d had plenty of exposure.

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Aimsley’s Reflections on Radiation Exposure and Child Birth

 

Further to his point and with a scrapbook spilling old newspaper cuttings he tossed the idea out there that men who worked around radiation had a tendency to father boys. “I had six boys before my seventh was a girl. I thoughtfully gave this considereation as he tapped a newspaper article that seemed to back the point.

You ever watch the Simpsons? Homer’s first born was a boy! That settled my doubts and aimsley concluded sweetly in a whisper “That’s what you get when you work for Mr. Burns”. Henry nodded in agreement. (excerpt from Rockhound: An Experience of the North)

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What Uranium Teaches Rockhounds About Bancroft Pegmatites

 

Uranium serves as a critical indicator for rockhounds, teaching them about the formation, composition, and economic potential of pegmatites. Because uranium-bearing minerals like uraninite and betafite often occur as primary minerals in pegmatites, they act as "trackers" for identifying highly evolved, volatile-rich igneous bodies.

 

Understanding uranium geology helps you:

• Read pegmatite systems

• Recognize mineral associations and geological transitions

• Understand fluid pathways

• See why apatite, titanite, monazite & uranium occur together

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Here is what uranium teaches rockhounds about pegmatites:

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1. Indicators of "Evolved" and Rare-Metal Pegmatites

• Late-Stage Crystallization: Uranium acts as an incompatible element, meaning it does not fit easily into early-forming silicate crystals. Therefore, it tends to concentrate in the final, most evolved, and volatile-rich melt phase.

• Connection to Rare Metals: Uraniferous pegmatites often signal the presence of other valuable, rare-earth, and critical elements, including tantalum (Ta), niobium (Nb), beryllium (Be), and lithium (Li).

• Mineral Association: When prospecting, finding uranium (often detected via geiger counter) often correlates with finding potash-feldspar-rich, smoky quartz-bearing zones. 

 

2. Identifying Specific Geological Environments

• Peraluminous Signatures: Uranium is commonly associated with peraluminous (biotite-rich) and peralkaline pegmatites.

• Core Zones: Highly evolved pegmatites often have cores of smoky quartz and pink feldspar, which are the most likely spots for finding both uranium minerals and associated rare, colorful, or well-crystallized minerals. 

 

3. Dating and Geologic History

• Geochronology: Uraninite, the primary radioactive mineral in these rocks, is excellent for dating. The decay of uranium into lead allows for the precise dating of the pegmatite's crystallization (e.g., in the 2.5 Ga range for some Canadian examples).

• Fluid Movement: Secondary uranium minerals (like green torbernite or yellow carnotite) often indicate where fluids have moved through the rock, causing alteration. 

 

 

 

 

 

 

 

 

 

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Entire communities formed around uranium production. Serving the Bicroft Mine, Cardiff was established in 1862 and by 1867 had 37 people. In the 1950s as many as 500 people were employed so when the mine closed in 1963 it was left scrambling to re-invent itself.

 

Dyno Estates and the Uranium Mines Lifestyle

 

Dyno estates still sits in amiable decay alongside Dyno road. Workers from the Dyno Mines lived there and its driveways are said to set your Geiger counter to panic mode. “it’s a great place to retire” or so they pitch the Dyno lifestyle" in local papers. At the first closing of Bicroft mine, houses at Dyno estates went for no more than $4500 and to encourage retirees , each sale included a free rocking chair or a flight over Paudash Lake.

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Abandoned Mines and Modern Rockhounding

 

I stopped on one of the hot driveways to interrupt a barbeque and ask the locals how to find the old Dyno Mine (before it was rehabilitated). It was a rambling convoluted explanation. I was told to watch for deep pits that dropped off into blackness. “Threw a breeze block down one and I hardly heard it hit. There some real doozies back there. Fall down one and they aint never gonna find you.”

FAQ: Finding Uranium Minerals while Rockhounding in Bancroft

 

Is it legal to collect uranium minerals in Bancroft?
Yes — only on public land where collecting is allowed and with landowner permission on private property. Never collect from protected or rehabilitated mine sites.

 

Are uranium crystals dangerous to handle?
They are mildly radioactive. Safe handling practices — no dust inhalation, hand washing, and proper storage — make collecting low risk.

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What tools do you need to find radioactive minerals?
A Geiger counter, UV flashlight, gloves, eye protection, and sample bags. A shovel for digging in vein dykes - hammer and chisel for pegmatites.

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What do uranium minerals look like in the field?
They can be bright yellow, green, or orange coatings (autunite, carnotite), or heavy black masses (uraninite).

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Where are the best rockhounding areas for radioactives near Bancroft?

 

Generally - Pegmatites, skarn zones, and permitted dumps around Bancroft, Cardiff, and Wilberforce — perfect for anyone interested in crystal mining in Ontario.

 

Specifically - 

• Beryl Pit (Quadeville): Famous for Euxenite-(Y) crystals and abundant Allanite.

• Silver Crater Mine (Faraday): Known for Betafite, though it requires a hike and significant effort to locate.

• Faraday Hill Roadcut: A accessible site for Uraninite, located along the road. Uranite is found in small dark cubes along with small blue apatite.

• Kemp Prospect: A site with high radioactivity, offering Thorite and Uranothorite in a pyroxene skarn.

• J.G. Gole Quarry (Madawaska): Known for producing Fergusonite and Euxenite crystals

• Greyhawk Mine was accessible last I checked. The tailings are heaped alongside an ATV trail.

• Kenmac-Chibougamau Mine: All radioactives in a fissure 20 feet wide and 500 feet long

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Note: inclusion in this article does not imply permission to trespass. Always check on surface and mineral rights and seek permission to rockhound when needed.

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About Michael Gordon – Dark Star Crystal Mines

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Michael Gordon is a co-founder of Dark Star Crystal Mines, Bancroft, Ontario and a lifelong rockhound, mineral educator, and ethical crystal advocate. Through ethical crystal mining in Canada, Michael focuses on education, safety, and preserving the integrity of Earth crystals from Bancroft. He has a degree in geography and a diploma in gemology. Michael is author of the 3-part rockhound series books and also curator of the popular you-tube channel - Caver461.

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