Cobalt, Ontario rockhounding Guide: Silver History and Exploration by Michael Gordon, Rock and Gem, May, 2006

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The Discovery of Silver in Cobalt, Ontario

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When J.H. McKinley and Ernest Darragh were employed under contract to supply wooden ties to the Temiskaming and Northern Ontario Railway, they scouted just ahead of the rail line, chopping down trees and piling them as ties along the expected route. Whether it was the sun’s reflection on an exposed slab of rock or the opportune recognition of a silver nugget along the shores of Long Lake, something drew their attention to the incredible mineral wealth beneath their feet. The sign now marks the town of Cobalt, Ontario, right where they first discovered native silver—sparking what would become the largest silver rush in Canadian history.

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What followed was undoubtedly the biggest silver boom ever known. Deep fissures of high-grade silver ore assayed at up to 4,000 ounces per ton, creating a seemingly inexhaustible supply that flooded world markets with over 420 million ounces of pure, virgin silver within a single decade. Today, Cobalt remains legendary for its rich mining history, classic silver veins, and world-class specimens. There is still plenty of silver and associated minerals for modern explorers, making rockhounding in Cobalt, Ontario a rewarding experience—and the historic mines and abandoned workings add an unforgettable layer of adventure for collectors visiting the Cobalt silver mining district.

 

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​How the Famous Cobalt Silver Veins Formed​

 

The world-famous Cobalt silver veins of Ontario formed when super-heated hydrothermal fluids rose through fractures in some of the oldest rocks on Earth. These host rocks are Precambrian and Archean in age, meaning they are among the most ancient exposed crust on the planet. As the mineral-rich solutions cooled near the surface, they deposited their loads of native silver into narrow cracks and fissures, creating thick, sometimes nearly solid veins of metal that made Cobalt legendary among collectors and miners.

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Cobalt's Structural Geology and Mineralogy

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What truly controlled the location of these spectacular silver deposits were two dominant structural features: the Cobalt Fault and the Valley Fault. These major faults acted as deep conduits for mineralizing fluids rising from the Earth’s interior. The Cobalt Fault alone produced over half of all the silver ever mined in the district, with some veins assaying at thousands of ounces per ton. Most historic Cobalt Ontario silver mines were located directly along these two fault zones, making them the backbone of the entire mining camp.

 

Along with native silver, the hydrothermal fluids also carried cobalt and nickel minerals such as niccolite and skutterudite. Early miners focused only on high-grade silver and discarded lower-grade silver and cobalt, unaware of their future value. Years later, these old mine dumps were successfully reworked, producing large quantities of both cobalt and silver and reinforcing Cobalt’s status as one of Canada’s most important historic mining districts.

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The veins cut through dark diabase and greenstone, often locking silver into rough black rock, though the most prized specimens formed as delicate wire silver in white calcite. Beyond silver, the Cobalt mines yielded major amounts of cobalt, nickel, bismuth, arsenic, mercury, and gold. Even so, these impressive byproducts were overshadowed by the staggering volume of silver that made Cobalt one of the most famous silver camps in the world—and a key part of the mineral heritage celebrated at Dark Star Crystal Mines.

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Rockhounding in Cobalt Ontario: Collecting Silver and Rare Minerals

 

The act of collecting minerals is, to me, as much about the rock as it is about the experience. In Cobalt, Ontario, the collecting opportunities are plentiful. The town grew literally on top of the strike. Great heaps of tailings crumble out into silent lakes; they hold a pirate's ransom in silver nuggets, plates and wire. As for   the experience, it is absolutely unforgettable. You savor the remnants of a romantic turn-of-the-century enterprise. everywhere you look , the debris of that long-ago time is scattered; ore cars and mining machinery protrude from amongst the dappled yellow birch, and rusting head frames rise from the forest    like decaying church spires.

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Those who venture here can still experience something of that mad scramble, in the wealth that's still locked   in undiscovered veins. In 1905, Willet Miller, a Government geologist, pointed out that native silver occurs   a result of the decomposition of sulfide ores, which generally takes place within 80 feet of the surface. Bismuth can also be found in well-formed crystals. The mineral erythrite, a hydrated cobalt arsenic, sometimes appears in crystalline form as a delicate pink rosette. When heated, it takes on the characteristic color of "cobalt blue". This color change phenomenon is characteristic of all hydrated cobalt salts.

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The Value of Silver and Crystal Specimens from Cobalt

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A certain economic value is attendant to your discoveries here that may be lacking in other places. Though silver is said to be the "poor man's gold", enough of it will make you rich. As Sandy Cline reported in his article, "A Tour of the Cobalt silver Mines" (1982 silver and Gold annual, WWW.geocities.com/SoHo/gallery/4821/TH/tour.HTML), a visitor to the area in 1906 briefly toured the mines and picked up over $15,0000 worth of silver nuggets. There are many stories of forgotten mines and hidden stashes in the forest. It is that lure of lost treasure and treasure yet to be discovered that draws rockhounds from across the continent. There is no shortage of rare and valuable mineral specimens. and finding an undiscovered vein or lost horde is a very real possibility - case in point, the recent discovery of the gold horde in the Great Canadian treasure hunt; add to this the possibility that Cobalt still has more to give - gold coins, cobalt for batteries and a lucrative deal with American Defense contractors for strategic minerals.

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Specimens and silver crystals found in cobalt are valuable far beyond their simple weight in ounces. a typical silver crystal can sell for between 430  and $6000 depending upon its quality. Coils and loops of silver wire are found in the veins. Rockhounding for silver in Cobalt can bring you any of many variations. Sometimes these oddities are tightly wound into balls-and knots that incorporate other mineral specimens. Most bizarre of all are the dendritic wanderings of the strangely formed silver trees. skeletal limbs  stretch outward from the nuggets though they were once a living plant. This same dendritic silver is found  in pink calcite at the Deer-horn Mine; it's a prize that's especially valued by rockhounds.

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Best Places to Find Silver While Rockhounding in Cobalt

 

According to Cline, one of the best places for novice treasure hunters to rockhound in Cobalt is at the Lumsden Mine. The output from that site was only around 20,000 ounces and the tailings piles have already been sifted over by rockhounds with metal detectors. Cline says that, because of the high mineral content in the local rock, most metal detectors have only limited penetration, but by clearing the surface, you are able to locate the silver further down than those who have preceded you.It is still possible to find small silver plates in this spot and wherever others have not already trodden.

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Finding a Silver Nugget in Cobalt, Ontario

 

Ralph Schroeder, President of the Northern Ontario Rock and Mineral Club, gets highly animated when he remembers the first time he found a silver nugget. He had been investigating with has mine-lab metal detector in the vicinity of a mine near Silver Center, a settlement to the south of cobalt that has made the transition form a sleepy village to a true ghost town. The ore from this site had been roughly sorted , and anything that was not immediately recognizable as high-grade ore was discarded and used as road fill on the access track. When a beaver dam broke, the ensuing flood washed a section of road away; the poorly sorted rock was spread through the creeks and surrounding woods. as he tromped up the middle of a stream bed, streaked with sweat and half eaten by black flies, Ralph noticed a dull glint beneath the water. Bending down to investigate, he found a nugget weighing about an ounce.

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Nipissing Hill and the Richest Silver Mines in Cobalt

 

Arriving in Cobalt as the evening crept on, I found it to be a charming and yet lonely place, just a few winking lights in the vastness of northern forest. Around a curve in the road, Long Lake slips into view. On the banks across the water, grim, black chasms cut into the rock and the murky green lake has flooded in. this was my first view of Nipissing Hill and the famed Cobalt silver mines, birthplace of Canadian hard rock mining.

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In it's heyday, the ridge was known as "The Nip"; the once forested protrusion was entirely stripped of its overburden by high pressure water hoses. It now lies bare and bleached, a rocky skull cleaved by blackened crevices that ooze mineral stained waters. it was the site of the richest silver mine in the area, indeed one of the most bountiful veins in the entire world. from that one property, over 91 million ounces was extracted. On top of the Nip, stacked within the foundations of a processing facility, there are packed crates filled with ball bearings the size of quail eggs rusted into sugary orange lumps.

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Silver Mines in the Dark: Cobalt Night Exploration for Rockhounds

 

On a stroll that night, I was immersed, in the hollow windowed, tin sided ambience of the place. beneath a glowing yellow sign that proclaimed "Miner's Tavern", a stairway led down to a cellar, from which I could intermittently hear the roar of beery laughter and the tavern door slamming as the patrons came and went. Within there was the warm glow of companionship and sociability as the rest of the town sulked in gloom and decay. . The glory Hole, a gargantuan shaft and attendant head-frame, were especially atmospheric in the dark. There at the edge of the settlement, a pit drops down to a deep pool.  ore skips are lined up nearby on a narrow-gauge track and above, like a looming specter, a rust streaked tower creaked eerily in the wind. I was warned that wandering carelessly in the bush could be fatal. There are pits just barely concealed by rotting timbers beneath the forest floor.

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Speculating as to how the workings were laid out is all part of the Cobalt experience. If you can trace the old route between the diggings and the smelters, you are likely to find many slabs of high grade ore. Imagine the careless clattering as silver bearing rock slipped from over-loaded carts into the roadside ditches It is along those forgotten arteries that rockhounds with metal detectors are often found. sometimes without apparent reason, sizeable pieces of silver are found deep in the bush, well away from any known deposit. Ontario rockhounding collectors speculate that the unregulated use of explosives contributed to this deposition. an ambitious quantity of black powder could hurl glittering hunks a quarter of a mile from the vein.

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 The Geology of the Cobalt Embayment and Silver Deposits

 

Silver is most profusely concentrated around the town, but in truth,  the wealth impregnates a sizeable chunk of the Cobalt Embayment. This is a 120 kilometer wide patch of ancient sedimentary rock that is richly laced with silver bearing veins and even gold. along its thinning north eastern rim. In their core, these veins are clogged  with calcite, white quartz's and feldspars line their outer edges. The silver is usually sandwiched between these two minerals, the whole structure leading steeply downward until it pinches out or becomes unprofitable. these mined out trenches dissect the countryside, making any woodland ramble an exciting and eventful excursion. 

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Miller in his 1905 Bureau of Mines Report "The cobalt Nickel Arsenides and Silver Deposits of Temiskaming, Part II" (1905, L.K. Cameron 2nd edition), says that the rocks of the area consist of exposures of the lower Huronian strata that overlie the Keewatin green stones. This whole assemblage has been intruded by a series of Diabase dykes. The silver ore is thought to have been leached from the local green stones or to have risen from far below with the diabases.  Super-heated water is thought to have been the medium in which the silver ores were transported.

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A Silver Mine that had the largest ever piece of solid silver - The Lawson Vein

 

The most spectacular of all silver discoveries  was the Lawson Vein. Few believed the possibilities, but prospecting in Ontario really paid off this time. It was the largest single mass of solid silver ever found. From a crevice no more than 100 meters long and 3 feet wide, the miners dug 1250 cubic meters of 75% pure silver. This equates to over 10,000 tons of metal. Here the issue was not how to find the silver, but how to mine it! A solid mass of silver is not easy to break down into managable pieces, but some clever miner realized that by blasting on one side of the vein and then the other the silver would bend back and forth until it snapped. The four mine owners retired wealthy, and you can still see the fenced off trench from which that great chunk of metal was extracted. It was a vein that became known as the "Silver sidewalk".

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Properties of Silver and How Cobalt’s Ore Was Identified

 

Silver is the whitest of all metals. It reflects 95% of the light that strikes it, and for that reason, it is typically used as a backing in mirrors. McKinley and Darraugh, the initial discoverers of cobalt's silver wealth, had both been gold prospectors in the California gold rush. By their experience there, they had learned to test for silver by biting a nugget and then assessing the surface indent.

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Pure silver is too soft for regular wear so it is mixed with 5% copper to make sterling silver, a much harder alloy that is used in jewellery and table wear.

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I had wandered out early on my first misty morning in Cobalt; it was a beautiful time to see the area. A soft, grey misty like dove's feathers drifted off the lake. The town across the water still slept. I used this time to explore the old mine workings;there are said to be more than 400 abandoned sites in the area, a significant proportion of the 6000 neglected mines that are said to litter the province. Many of the more impressive shafts around the town are fenced, and the confines of their walls, ageing grey timbers are propped like railway trestles.

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At the edge of an abandoned factory, I met two young men. They materialized from the mist like phantoms. It was a most surreal meeting, ""Morning, eh". it is the greeting by which polite northerners recognize each other.

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I was told that it had once been a popular pastime to explore the underground tunnels. there are many miles of passage down there, and older residents reminisce on candle-lit explorations where they followed rusting railway tracks beneath the surface, bridging yawning chasms that dropped down into nothingness. Kids teetered  across cast iron pipes that supplied compressed air to the mines.

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Cobalt’s Abandoned Mining Tunnels and Shafts

 

One of the locals that I met spoke about a crevice that he crawled along under the town, an old abandoned mining tunnel. Going under there is pure Cobalt mining history and  tunnels and old mine shafts are everywhere. When he finally emerged into daylight, the explorer was at the bottom of the "Glory hole." The whole nature of this settlement is one in which the town and mines are inextricably linked; the surface and subsurface coexist as one. Buildings overlie fabulously glittering silver veins. Old timer, Leo Dagenais recalls a story of a lady who while kneeling in her flower bed, suddenly saw a drill poke through the soil  right in front of her, it's something to consider when you are rockhounding - make sure your boots are steel shanked. Visitors can explore this amazing multi-dimensional  landscape by taking an adit tour, It starts at the museum. You follow an experienced guide down into the Colonial Mine, where there are 16 miles of tunnel. The site yielded 10 million ounces of silver, and its passages have been scaled and bolted to provide safe exploration for tourists.

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How to Identify Silver and Cobalt Ore in the Field

 

The previous day I had visited Ralph Schroeder and Andy Christie. Ralph is Cobalt's resident gemologist and Andy owns the Princess Sodalite Mine in Bancroft. Both are old friends and extremely active in the Ontario"rockhounding community". They told me that the best place to find silver was where it had already been found (much like it is with most crystals - few places are tapped out when it they are said to be). I was assured that I'd come to the right place for that.Andy, a kind and soft spoken Scott, advised me, "If you want to find silver, you gotta know how to look". Cobalt and silver are typically mixed together. Cobalt reveals itself by a pink blush on the outside of the rock. If you look for cobalt, you are likely to find silver as well". The gaudy color is a phenomenon that's commonly called "Cobalt bloom".

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In the old days, the silver miners had been told to follow the white seams of calcite because the element was concentrated in those veins. Around the town of Cobalt, a low grade yield from the silver mines was usually around 100 ounces of raw silver per ton. "Today folks will work a mine for 50 ounces/ton, says Andy. "Feel the weight". I am offered 2 sample rocks of similar size. I heft a block in each hand and note the difference. The silver bearing ore is far heavier than the country rock, though both are a dismal grey on their outer surface. Ralph points out that the high grade ore was removed from narrow fissures, so it generally appears as flattened slabs. 

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Splitting the heavier of my two samples with several sharp hammer blows, Ralph revealed the glittering innards of the tarnished rock. It was granular in appearance with the color of aluminum, but with much greater luster. I was assured that it was a high-grade mixture of cobalt and silver. the lighter rock was also granular inside, but with a color like lead and a far lower luster. It was a lesser grade ore that was rich in cobaltite. Ontario silver mines deliver a cocktail of mineral species. If you are rockhounding in Cobalt, be prepared to find anything.

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"You can find silver by feel", Andy tells me. "Just rub your fingers gently over this corner here and see if you can notice the edges". I was unable to detect anything unusual. I closed my eyes on Andy's advice, and the protrusions instantly began to catch my skin. "It's sharp like tin-foil Ralph shouted above the excited barking of his Doberman, Phoenix. "Not too hard or you will flatten the spurs".

 

I leave the two friends as they are planning a diamond hunting expedition. Several kimberlite pipes had been discovered just north of the town, and half of them are diamondiferous. Over the last century, many stray stones were found scattered over the Great Lakes area, eroded from pipes in this North-eastern part of the province. they had been dragged south by glacial ice.

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In the gravel bars of nearby streams, Ralph and Andy hope to find a diamond crystal. Ralph has the idea of using an ultra-violet light to detect the stones. Some diamonds fluoresce under that stimulation, and strangely enough they seem to be occurring in Cobalt's  breccia that's exposed in places along the side of the highway and in between the mine workings. If you need to know where to find crystals and silver in Cobalt, these fellows are the ones to show you.

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Silver Mines in Ontario Tainted by the German Kobalt

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Cobalt ore is often comprised of the pure element cobalt, as well as arsenic and sulfur. the silver mines of Saxony and Bohemia were greatly affected by this polyglot metal, and those who smelted it slowly succumbed to its toxic effects.  arsenic was the main culprit.  Miners either inhaled or ingested it and though it had been used prior to 1943 to combat syphilis, its poisoning victims became paralyzed and delirious.

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A shady little goblin called a "Kobalt" was said to be responsible for this tainted ore. German miners claimed that it was he who mixed cobalt with the silver ore. Kobalts had supposedly been seen skulking in the shadows of dark and lonely places, and special prayers were offered to protect the underground workers. It was from the Kobalt that the so-called half-metal got its name. Cobalt was not fully recognized as an element until the term was re-defined in the latter half of the 1700s.

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Finding Silver at the Langis Mine in Cobalt, Ontario

 

For finding silver in Ontario it pays to go outside the usual traveled places. This particular mine is a little off the beaten path - less traveled so less picked over. Popularly known as the Langis Mine after the Langis Silver and Cobalt Mining Company that operated it in the 1960s, the Langis is famous for producing some of the world’s finest dendritic silver and high-grade ore specimens. Many pieces consist of sawn chunks of vein material that reveal a “herringbone” crystal patterns of native silver, often coated with arsenide minerals within carbonate veins. In some cases, the carbonates can be carefully leached with acid to expose exceptionally sharp crystal structures. The mine is located about 12 miles north of Cobalt at the north end of Lake Temiskaming near New Liskeard, on an isolated patch of Cobalt sediments intruded by Nipissing diabase.

 

Numerous silver veins were discovered and developed on the property of this silver mine, with the most productive occurring near the No. 3 and No. 6 shafts and a less productive zone between them. Veins near No. 3 generally strike northeast or northwest, while those near No. 6 trend north of west to northerly. All ore shoots occur in steep veins cutting relatively flat-lying Huronian Coleman Member silt-stone and conglomerate beneath a Nipissing diabase sill. Access from New Liskeard is via Highway 65 east for 12.7 km to Langis Mine Road, then south following successive forks (left, left, then right) to the rehabilitated No. 6 shaft area, followed by a short 100 m foot traverse to the east-northeast.

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Cobalt Ontario: A Historic Mining Town with a Dark Past

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Silver does not have the same magical lure as gold." Doug shear, Project manager for the historic Cobalt Mining Camp tells me, but the strike here was much more significant that that which occurred ion the Klondike. I mean the depth of history here is just beyond belief." He pointed out a non-descript siding structure that is now the senior's center. It used to be a Chinese laundromat. One evening a customer walked in and all the machinery was running , food was cooking and water was boiling on the stove, but the entire family had vanished. they were never found, and to this day it is a mystery that still haunts the town. While rockhounding they might still be found by someone at the bottom of a hidden shaft, the deeper ones going down below 200 meters.

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The whole atmosphere of Cobalt is a little eerie; there is a Gothic tension that pervades the old mine workings. I suppose the ever-present past can be a little unsettling; it is a historic mining town where you can still see the history untouched in the bush and the rock. While you are exploring Cobalt silver Mines and it's old workings you sometimes inexplicably feel a chill. You're constantly reminded of the hidden landscape that exists in the darkness beneath your feet. There are vast drops and tunnels last trodden, in some places over 100 years ago.

 

In the twilight you stand amid obsolete machinery, dredged up from below and scattered along the edges of mirror smooth lakes. I watched the shadows stretch across the bluish-black water. My attention is drawn to a dismal looking elevator cage. Its a box no bigger than a phone booth. several miners would squeeze into each such canister for a harrowing drop into the depths. Some of the area's tunnels probed silver veins 1600 feet beneath the surface. Rails in the bottom of the cage allowed the insane inclusion of a shifting ore skip. About half of the accidents that occurred in 1906 were related to falls from these enclosures.

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Cobalt Is One of the Best Rockhounding Destinations in Ontario

 

Ontario Rockhounding and collecting possibilities in Cobalt are quite remarkable. Though it is a significant drive northwards from Toronto, it will be one of the premiere rockhounding adventures in Ontario. At these old Ontario silver mines you will find unique mineral specimens, and at the same time , experience a raw, unsanitized past. Up in the northern wilderness a veritable treasure trove of history awaits your exploration. And while up there you can book any of several rockhounding experiences. There are the standard trips and ask around town for something a little more adventurous if you wish.

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Author Bio

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Michael Gordon is a Canadian rockhound, geographer, and author with over 30 years of experience studying Ontario pegmatites and gold deposits. He holds a degree in Geography and a Diploma in Gemology and is the author of the Rockhound Series. You can purchase the Rockhound series here.

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Work Cited:

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Gordon, Michael. “Cobalt: A Northern Treasure Map / The Ontario Town with a Silver Lining.” Rock & Gem, May 2006, p. 80.

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​Sergiades, A. O. Silver–Cobalt–Calcite Vein Deposits of Ontario. Mineral Resources Circular No. 10. Toronto: Ontario Department of Mines, 1968.

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Last updated 2026

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