Lazurite - Ontario!

Having a problem with this one. Surely Afghan. I want to believe... but...

I'll let Michael tell the story, but my first concern was that some collection with Afghan material was added to a rock pile in Ottawa, but NO!!! The piece as it was found was a waterworn cobble!!! So somewhere in Ontario there is or was a killer Lazurite locality.

Read the story, and remain entirely skeptical. No offense intended to Michael. Would love to see the entire find in person.

WOW!... Lazurite in Ontario!!!... and perhaps right in my neighbourhood... I must double my collecting efforts!

We find lazurite xenoliths in the Arkansas syenites all the time. Why would it be so unbelievable that an erratic was carried from a similar syenitic source? There are certainly enough syenites in the area.

Henry Barwood
Troy University
Troy, Alabama USA

Welll... the province has been well and truly scoured by collectors, miners, and prospectors, many of which would be clued in enough to notice a brilliant blue mineral and report it. I want to believe, but meh.

It reminds of the Rhode Island cop in the movie Me, Myself, and Irene. White guy with a white wife... and they have three cherubic, very black, children.

Something's off.

"Welll... the province has been well and truly scoured by collectors, miners, and prospectors, many of which would be clued in enough to notice a brilliant blue mineral and report it. "

Nonsense. Most rock is covered by heavy vegetation. Collectors, miners, and prospectors have seen, at most, 5% of rock in a given area of the Grenville (maybe a little more in the Bancroft area). Lazurite, often associated with easily eroded marbles, could very well be covered by glacial till or sand in lowlands. I sometimes have trouble finding historic localized occurrences in a 1 x 0.5 km wooded area (several still elude me after days of systematic work) - and these were found and recorded!

Were any detailed mineralogical / petrological investigations done on this lazurite-bearing cobble? Is the paragenesis the same as in afghan material? Franz Bernhard

There is definitley lazurite noted from Kimmirut, Baffin Island, Nunavut, and while this is far north of Ottawa this is still within the possibility of it having been carried by glaciers as Henry suggested.

Even when rocks are right in the open they could be disregarded. Carletonite was thought to be sodalite until they discovered it wasn't, after having sent truckloads upon truckoads of it to the crushers. Since quarry workers are not paid to care about recognizing lazurite or any other collectible minerals it may be that any source that was uncovered may have been ignored and sent to the crushers without a second thought. *sigh*

Hopefully the source is an Ontario one and that it didn't succumb to the crushers and is out there still waiting for us.

Good Luck, John!

Regards,
stephanie

Thanks Stephanie, but Phil is the more likely candidate to make this discovery...and I sure hope he does!
John

Phil is right on target here. From my perspective as a glacial geologist, the bedrock source of this material very likely may be covered by glacial sediments.

Woody Thompson
Maine Geological Survey

Stephanie, the Baffin Island material looks nothing like this stuff, in my experience. The tray of cabs I saw were more denim in color, and solid, not splotchy brilliant blue on white. So an unlikely source, I think. The truth is out there!

Dear Rob,
in my years, students of Moscow University had field petrographic practice on Ural. After its finish some of students, being in the middle of USSR, had prefer not return back to Moscow immediately, but had visited some more eastern regions or Central Azia deposits (to save money for train).
One group of students visit Slyudayanka region. They had camp on Slyudyanka river close to quarries. Of course they had collect a lot of nice skarn apatite specimens and part of specimens collected on Ural was thrown out from their saks.
Some years later well water worn pebbles of chromite ore were found under bridge over Slyudyanka river in Slyudyanka city by local geologists. This was the reason for Irkutsk Geological Service to begin survey works for chromite ores in upper flow of Slyudyanka river, where small hyperbasite massifs were known. BUT more close investigation of found pebbles had allow to recognize them as typical Al-rich magnesiochromite of Saranovskoe deposit on Western slope of Ural.
Students samples, during 5 km long way of their transportation by Slyudyanka river from the camp place to the bridge, become water worn quite naturally.

Yes Tim, the material I have seen and obtained from Brad Wilson is not as vibrant, however that does not mean there wasn't better stuff, the quality varies in the Afghan deposits as well. In any case I agree, the truth is still out there and let's hope the mystery can be solved!

regards,
stephanie

Thanks Pavel. Strange things have happened andt that is a good caution. This cobble was located in a pile of rocks for landscaping and came from one of eight quarries. All were checked to no avail.

The material looks like Balmat, but the brown mineral is still unknown. When I get a fragment back I'll try to sort it out, but this is not from Balmat. The only Baffin material I have seen is turqoise blue Lazurite and usually wrongly labeled Hauyne. I haven't seen any ultramarine Lazurite from Baffin.

Here is a polished cab of material from Kimmirut, Nunavut, from Brad Wilson.
Cabachon is 8mm. Photo is best I can do in indoor light at the moment.
I'll upload it to the gallery when I can get a better photo as there are none there currently.

Wow, what a pleasant surprise to stumble upon this discussion!

Of course a situation such as Pavel describes cannot be ruled out.

That said, as Rob points out, all of the known specimens of this material (including the two pictured here) came from the one boulder my mother found. Before being broken-up, it was a uniformly tumbled, apparently glacially transported cobble. Except that it was the only piece of lapis, it seemed entirely consistent (or at least, not inconsistent) with the other stones in the lot. Externally, there was nothing to suggest a different origin from the rest.

Identification, analysis, research, and field-work was led by the venerable Dr. George Robinson. Now, I'm not entirely sure how much work was done, and although the team was unable to locate any more of the material "in-situ" (either in the landscaping yard, a gravel pit source, or the original occurrence), in the end, he was reasonably satisfied that:

[1] The specimen is very likely to have come from a gravel pit in the Ottawa area.
[2] The material was entirely unlike that from any likely known occurrence (while it is possible it's from Baffin, the known occurrences were ruled out).
[3] And that the original in-situ source is/was likely in Ontario or Quebec (I'm sure George would have considered Balmat if it was similar).

Obviously nothing is entirely certain, so remain skeptical if you will, but an Ontario/Quebec origin is at the very least entirely possible, and I trust George's opinions on this. I'll ask him to weigh in though, just in case I'm remembering anything incorrectly.

Cheers,
Michael



Edited 1 time(s). Last edit at 06/07/2012 03:53AM by Michael J. Bainbridge.

Thank you Stephanie I have now seen ultramarine Lazurite from Baffin!!! The more turquoise bits are what I had previously seen.

Actually, I take back my earlier statement...

Two things are certain:

1 - It was found in the landscaping stone at the Ottawa General hospital, and
2 - Until someone comes up with evidence to cast reasonable doubt on an Ontario/Quebec source, that's my story and I'm sticking to it!

Rob & Stephanie, the Baffin "green" and "blue" are apparently from two different (although relatively close) locations. I forget if it was Brad Wilson, or Bob Gault who told me this, but it was from one who had been there.

M

Hi Michael
There is a BIG construction job taking place at this moment at the Perley Veteran's hospital just down the road from the Ottawa General!!... and it so happens I have folks to visit there...so I'll be packing my pick in my briefcase



Edited 2 time(s). Last edit at 06/07/2012 11:53AM by John Montgomery.