I am by no means a professional rockhound. My education is as both a gemologist and a geographer, but I believe both rockhounding (collecting minerals) and my other great interest – caving have been in my heart since childhood. And where better to rockhound than Bancroft, but a word of caution, as both rockhounding and caving appear on my site. Both activities are related to rock, but neither should ever meet. Cave mineral deposits must stay in the caves and a caver who shares both interests (and there are many) should never let their inner rockhound loose beneath the surface.
Wearing my rockhound persona this past Saturday afternoon I headed out to the Bancroft Chamber of comerce to get a vibe on the local collecting possibilities. For a place that styles itself as the mineral capital of Canada, they do very little to encourage that reputation. Remembering back to my childhood, rockhounding was everything in Bancroft – now it is just faded memories and hanging onto loose and fragile threads. Fortunately mother nature takes care of basics and continues giving back. I left the Chamber of commerce disillusioned – not by the staff, not their fault, just the general malaise of the people who call the shots. No effort to justify the reputation.
Anyway I picked up an ice Cap from Tim Hortons and headed off on a kind of aimless ramble, and within about half an hour I’d come upon a spectacular crystal vug (cavity) from which I spent the next few hours scooping crystals.
It was a calcite seam within a road cutting that had been opened by someone else and then abandoned as they obviously did not know what they had found and if they had looked within the cavity when they hammered it open it would be they not me who was posting the pictures.
My point is, you just need to know what to look for. Bancroft is famous for its calcite intrusions, a mineral that solidifies last from molten rock and so it acts as a medium for other minerals to grow in. The vug that I extracted crystals from was predominantly filled with amphibole and feldspar crystals and lying loose in the bottom of the part of the cavity that I dug into were a few doubly terminated crystals – having grown in the medium as opposed to being attached to the cavity wall. In retrospect, looking at the video it becomes obvious that the seam runs on an angle and there is likely to be a lot more to be extracted if rockhounds just follow up and down along the incline of the seam. As this rock cut is in a public place I will just leave its exact location for you to figure out, but there is enough in what I have said and shown on the video for you to quickly pin-point the general vicinity of the deposit.
Between 1953 and 1955 Croft Uranium Mines worked the area for radioactive minerals. They found betafite, uranite, uranothorite, allanite and pyrochlore. Their appearance is flagged in the pegmatite by a dark red color and quartz that has darkened to a grayish-black. There are also said to be small pink garnets in the gneiss and larger specimens in the pegmatite – some reaching up to 3 centimeters in diameter.
A couple of hundred meters along the mine road I got Maggie to pull over in a little clearing and I continued on foot, leaving her there with the understanding that I would be back as soon as I had found the mine and explored the dumps. She had Shaka with her for company and I had my whistle that I tooted on intermittently so as not to walk unexpectedly into a hunter’s ambush. The whistle also served the dual purpose of letting bears know of my presence as the bush was thick and close to the path and I had no wish to meet the “mother of all bears” in a circumstance of mutual surprise.
The road dropped steeply down into a valley and I soon realized that leaving the car above was a wise move. There was nowhere to turn around, the ruts got deeper, and the track was soon entirely underwater. Beavers had built a stick and mud palisade that held back a stinking organic tidal wave that would one day inundate the swamp below. As for the road, forget it. I climbed across on logs and waded knee-deep in mud, thinking what it might be like during bug season (What looks like a stream in front of the beaver dam is actually the mine road).
On the other side of the beaver dam the track began a slow and steady climb upward. I noticed the appearance of crushed granite where I walked and of course the telltale patches of eastern hemlock. These trees tend to grow in clusters wherever the natural forest has been disturbed. They tell you where to look for hidden human habitation.
I soon discovered the mine dumps on my left and in a marshy gully I unexpectedly found the adit.
See another abandoned uranium mine in Ontario … here or my trip to the Sarnac Zircon Mines … here (where we were again terrorized by the possibility of being eaten by bears
At first glance the Essonville Road Cut looked much like many others in the area – gnawed upon by rockhounds and strewn with shards of calcite and sand. Most immediately obvious were the huge black crystals that protruded from the calcite – a dyke that is theorized to run off into a southerly direction onto private property. A sign on the fence behind the cutting advertises “Rockhound Eco-tours”. A rockhound eco-tour? It almost seemed contradictory.
“You’re a rockhound?” I asked the fellow crossing the road from the pickup he had parked on the opposite shoulder – “You might say that”, I was told with a grin. “I am more a prospector and I operate the eco-tours – like to show the minerals on my property but we prefer not to set pick or hammer to them. We like to think of ourselves more as stewards”. “Stewards?” “Yeah, caring for the land. I know it sounds hokey, but I think we were meant to have our property – to look after it. Collecting can be destructive”.
I kind of edge my rock hammer around behind me. “Is there a problem with us collecting here I ask? Nah, its public land. Place is already trashed with all the blasting”.
In reverent terms Mark explained, what had formed in the cutting was Fluor-richterite. You will notice that some of the crystals have a metallic sheen – kind of stained by an iridescence, Its only a skin of goethite, beneath it is still fluor-richterite, one of the few minerals that can really be called “totally Canadian”. It was only distinguished from hornblende and recognized as a separate species in 1976”.
“So, in truth, you would have a hard time distinguishing between the two?” “Not really” my eco-teacher told me. “They are both amphiboles and they form a solid solution series, but fluor-richterite has a scaly white surface and it forms in prisms that are longer and thinner than those of hornblende”.
“Do you sell any specimens?” I ask hopefully. “How can you put a dollar value on them?” I am chastised.
As fortune would have it, I found myself in the company of Lee Clark later that afternoon. Having seen the township’s blasting Lee had asked for the debris to be dumped beside his barn; he had scooped the lion’s share – enormous boulders with fluor-richterite spines and as Lee pointed out hexagonally appearing prisms that cleave away in flakes. “phlogopite mica; they used it for windows in the old wood stoves.
Having weathered out of the calcite there were doubly terminated prisms lying amongst shards and unusually shaped prisms that appeared fully formed on the one edge and flattened on the other. I was in the process of trying to decide what unusual growth condition had so stunted the crystals when Lee apparently read my thoughts “The prisms frequently cleave down their center,” he slipped me a smaller perfectly formed specimen that he had been carrying in his pocket. “It’s my worry stone” he explained, “You take it; folks down south have greater use for that than I”.
Well, Rockwatching has been up and running for a number of years now (5 to be exact) and I believe it has contributed significantly to the interest of people like myself who like caving, rocks, the outdoors, gems and minerals in Ontario.
We are just a few short days from 2011 and I believe it’s high time we made some resolutions -all of us (you my loyal fellow bloggers as well).
So in the interests of all involved a few ground rules to follow on Rockwatching from now on
1) Lets not carry a personal vendetta onto this site which is meant to be a forum where like minded enthusiasts can interact in a positive way.
2) Lets respect each other and try not to get personal when we are frustrated.
3) Lets respect the basics of conservation and eco-minded thought.
4) Lets not assume stuff we don’t know for sure (hence the survey at the bottom of the post).
5) Lets keep in mind that this is all about enjoyment.
6) Lets keep in mind that just because the topic is on the table, every single aspect that pertains to it is not an open book.
7) Lets respect people who are not on the site, private property, reputations etc. Just because there is discussion of a site or feature does not mean permission has been granted to go there.
8) Lets not get petty, self righteous or important. Stop correcting my grammar, spelling or use of terms. I am a writer at heart and so I believe I can use the language as I please (providing it’s in good taste, or if I choose, not in good taste).
9) Lets not waste my time by having to re-direct you to one of the above rules.
You never know what you are gonna find at the Bancroft Gemboree and for that reason it’s always an adventure that I look forward to. The 2010 event was no exception. I met some old friends – Ralph Schroetter amongst them. I was grateful for the Oregon Sun stone that he handed me. It was a gift with a lovely peachy hue.
In retrospect, I really wish that I had bought one of these old beauties. The going price was $40 a piece. This appealed to both my caving and rock and mineral interests. The Carbide lamp burns acetylene which is produced within the lamp as a result of the reaction between Carbide (C2H2) and water. With the number of old abandoned mines up in the Bancroft area and the caves in the local marble, I would not be surprised if these old carbide lamps had seen local use. Check out the pitfalls of buying a carbide lamp here.
As usual, the better faceted and collector stones were found at the lower venue, while up on top of the hill the outside vendors displayed the greatest diversity of product. Year after year it seems the same vendors pick the same locations.
Check out these orthoclase feldspar crystals – or at least my guide told me they were orthoclase crystals. I have not had the chance to verify this.
I met an interesting gent who runs ecotours for mineral collectors. His philosophy is that the minerals should remain in-situ so that future generations can enjoy them. I had been picking away at a road cutting when my host approached me to introduce himself. Are you a rockhound? I asked.
I have since learned that Mark is more focused on preservation than collecting – which is good. It would be a crime to whack away at this beautiful specimens and turn them into dusty old rocks in someone’s basement. I will be visiting Mark again and if he is agreeable I will display some of his other amazing mineral wonders – all “in-situ” “As god has made them”. On Mark’s tour I saw huge horneblende crystals, long thin spines of fluor – richterite and plenty of red zircon.
Both the fluor – richterite and hornblende are amphiboles though they can be quite easily distinguished apart by the more squat and blocky nature of the hornblende. Fluor – richterite has a diamond shaped cross-section and so it is simply distinguished from a pyroxene family member which tends to have crystal angles at close to 90 degrees.
Following the release some time ago of my book "Rockwatching; Adventures above and below Ontario", I am pleased to announce the release of my new book "Tamarindo; Crooked Times in Costa Rica". It is a story of opportunity. Edgehill Press is the publisher. (www.edgehillpress.com)