May 25th 2008 and previous visits at the Demix Quarry in Saint Amable, Quebec

The Montreal Mineral Club organized a day trip to the Demix Quarry in Saint Amable, Quebec on May 25th 2008. I remember there was a time about 8 years ago when I could “smooze” the guards with my limited French and get a free pass to go into the Quarries to collect. However those days are long gone with tightened security. Fortunately permission is still given to the minerals clubs for some localities. I had to take advantage of this trip.
Before I enter the subject of this trip, I will share some of my previous finds from about 8 years ago.
On my first visit, I think it was in 2000, I found a blast had opened some larger vugs with natrolite crystals. This was the best natrolite find for me. I had noticed light gray clay spread on the blasted pieces of rock. This is usually a good sign that a cavity was opened. So I searched around the clay and found some nice pieces.

So often it is a matter of being at the right part of the pile after the right blast. I also found a pipe like vug about 6” long just laying amongst the stones. It had a analcime, natrolite, microcline, other minerals, and it had the largest rhodocrosite crystal I ever saw from this quarry. (20mm x 20mm)

On the May 25th trip we had a picture perfect day of nice weather. I followed most of the crowd and started with what was supposed to be the latest blast at the back end of the Quarry.
The Back end was the southeast end, furthest from the entrance. Most of the people started there and combed over the rock. To me the vugs seemed smaller than in other blasts. You can see the amount of loose rock from the last blast here.
I had the honor of speaking with Mr Lazlo Horvath, who is well known for his years of contribution to the mineralogy of Saint Amable as well as Mount Saint Hillaire. He has as his namesake the mineral horvathite. I also spent some time with Jonathan Levingner, who is an active collector from the Montreal region. Here Jonathan is displaying a boulder with a pipe-like vug with natrolite and other minerals. It was an interesting example of a larger pipe vug but after we examined it with a loupe it seemed not worth cracking the boulder apart. Mostly it had poor natrolite crystals.
I started the day looking over as much of this pile as possible, but I only found small vugs and thin seams. Saint Amable is a place for the micromounter after all. It has similar chemistry as Mount Saint Hilaire but the mineral crystalization is smaller. The cavities here are nothing like the pipes found at Mount Saint Hilaire.
I was picking up some thinner or smaller cavities here and took home my booty to look at under a lense. Here are some of the finds.
I found small balls of aegerine needles perched on white microcline plates. This is typical of this locality and one finds ubiquitous in these cavities. These were associated with clear crystals of natrolite.

Here to the left is a magnification of one of the vugs (FOV 15mm x 10mm) with the ball in the center having 2-3mm diameter.

Here to the left is a magnification of another small vug (Field of View is 20mm x 15mm) showing balls of green aegerine needles in the center. Reminding me of sea urchins perched on white microcline plates. To the right are clear natrolite crystals and some rose eudialyte.



This to the far left is another magnification (FOV about 15mm x 11.5mm9) of a serandite (5mm long), aegerine, eudialyte growing on microcline plates. Notice that the serandite are the pink prismatic towers in the center(displaying the pinacoid terminations), also with a ball of greenish aegerine to the right. Petals of eudialyte are on the top right, also there is micaceous silvery plates of polylithionite in the back. Second to the left is a 4mm x3mm magnified view of the polylithionite

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In another small vug from the same syenite was some managaneptunite. Crystals up to 2mm long exhibiting dark almost black color with red highlights. (FOV 10mm x7.5mm)




Another piece had eudialyte and a beige mineral which may be serandite or elpidite but is not really identified. Below I zoomed in on the beige mineral.

There were stubby prismatic crystals of a orange tan color forming crusts associated with these beige sheath like aggregates.


After deciding I gave enough time here I followed a group who were earnestly digging into a pile in the east corner of the quarry. Here some of the collectors scouring the fresh piles of rock at the back south east end When I climbed up to them I saw they were finding large but rough chalky analcime crystals. They were generous enough to share some with me. Later I found small (less 1mm or less) crystals perched on the analcime. The mineral is most likely identified as sphalerite, by its association, color, luster and crystal habit. Here below are two views. First photo you can see a 20mm analcime crystal with dark brown crystals perched on its surface. Second photo is magnified to show one of these crystals which is about 1mm. Note it is dark brown and has a resinous luster to it in the thinner parts.
After securing some samples here, I followed Mr Levingner who was collecting in a pile on the central floor of the quarry. He was interested in a lighter tan colored rock. The normal syenite here is usually dark gray, but this was a lighter tan colored rock. It had the same hard texture but seemed to be bleached. It may have been originated at or near the hornfels halo of the intrusion. The cavities again were really small and only interesting for micromounters. After taking this material to my laboratory, and putting under magnification, I again found more specimens for my unidentified cache.


One mineral I identified from these cavities is yofortierite with its distinctive bronze colored sprays of needle like crystals. You can see it as bronzy brownish spray of needles in a magnified field of view 4x3mm above right. The other mineral identified is fluorite crystallized as distinctive purple crystal on microcline plates. The magnified field of view is 4mm x3mm to the left.
Notice there are long platey or micaceous minerals associated around the yofortierite. You can see this in the third photo magnified to a field of view 4mm x 3mm. Also there is a yellowish vitreous mineral in the second photo which is the same scale. I haven’t been able identify these minerals as of yet.

Outside the fortunate find of the rhodocrosite, all my experiences at the Demix Quarry have rewarded me with smaller but fascinating crystallizations. Good material for micro photography.

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