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Modris Baum's Photo Gallery

DL6-GPCLabuntsovite Supergroup

Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 1.1 mm
Largest Crystal Size: 0.85 mm

This could be korobitsyinite, tsepinite-Na - or just plain old nenadkevichite. Qualitative EDS shows a Ti peak substantially higher than the Nb peak. Taken literally, that would imply korobitsynite or tsepinite-Na (which are chemically identical). But qualitative EDS can be misleading becuase Ti is detected more readily than Nb and because peak heights can depend on other factors besides the chemical composition.

In my own little world, I think this is korobitsynite, but I have posted it very conservatively here as "labuntsovite supergroup". Only WDS + XRD could say for sure. Not in my budget.

See the analysis "related" photo for the EDS scan. (There are also several other photos of this specimen that were posted as "nenadkevichite group". Strictly speking, tsepinite-Na doesn't belong to that group.)
Photo ID: 861107     Uploaded by: Modris Baum   View Count: 18   Approval status: Public galleries    Type: Photo - 1024 x 775 pixels (0.8 Mpix)

J80-97WNenadkevichite : (Na,◻)8Nb4(Si4O12)2(O,OH)4·8H2O

Multiple photos available
Demix-Varennes quarry, Saint-Amable sill, Varennes & St-Amable, Lajemmerais RCM, Montérégie, Québec, Canada

Field of View: 1.2 mm
Largest Crystal Size: 0.3 mm

These crystals are very tiny, so the photo isn't very sharp. But I like the habit.

There is a stereo child photo that makes things look a bit sharper.

Photo ID: 861100     Uploaded by: Modris Baum   View Count: 12   Approval status: Public galleries    Type: Photo - 878 x 1024 pixels (0.9 Mpix)

6RX-7JXVilliaumite : NaF

Multiple photos available
Demix-Varennes quarry, Saint-Amable sill, Varennes & St-Amable, Lajemmerais RCM, Montérégie, Québec, Canada

Field of View: 3.15 mm
Largest Crystal Size: 1.0 mm

Villiaumite is a rare mineral in the Saint-Amable sill. Mostly it occurs as cavity fillings, anhedral grains, or, at best, crude, etched/leached, crystals with an occasional face here and there. This is the best crystal that I have ever seen from here. It isn't perfect, but it is in pretty good shape and is even lustrous. (The dark zig-zag on the most lustrous face is actually a reflection even though it looks like a shadow in the photo). I don't think that any of the faces are cleavages.

According to the Min Rec special issue on this quarry (March/April 1998), villiaumite was first found here ca 1994. This specimen was found in November 1999, but I only noticed this particular crystal recently. As in the 1994-6 find, assocaited minerals include serandite, eudialyte, zakharovite, aegirine and natrolite, but there is no varennesite, makatite, or vuonnemite. Instead, there is (locally) abundant nenadkevichite, yofortierite and/or tuperssuatsiaite (none of these on this specimen) and a couple of unidentified mineras (including the yellowish stuff shown in the photo) currently awaiting EDS. For Demix-Varennes, this was a very rich find of villiaumite.

Photo ID: 860946     Uploaded by: Modris Baum   View Count: 16   Approval status: Public galleries    Type: Photo - 1024 x 751 pixels (0.8 Mpix)

KE2-6J6Hureaulite : Mn2+5(PO3OH)2(PO4)2·4H2O, Rockbridgeite : Fe2+Fe3+4(PO4)3(OH)5

Multiple photos available
Criminoso claim, Água Boa, Minas Gerais, Brazil

Dimensions: 6 cm x 5 cm x 3 cm

This is a new parent photo. Numerous new child photos and EDS scans have also been added. (Nov 2017)

At the macro level, this is an nice specimen of hureaulite from a lesser known Brazilian locality. There is also a substantial amount of massive/grainy dark green manganoan rockbridgeite (analyzed – child analysis scan #163).

But perhaps the most interesting thing on this specimen requires a scope to appreciate. It consists of numerous small, mostly pale blue, crystals that look like vivianite. But qualitative EDS shows far too much Mn in addition to Fe. You are not supposed to estimate element abundances from a qualitative scan. But I did it anyway, and came up with a rough estimate of P:Fe:Mn of 3:3:1. There is no such phosphate, but frondelite (Mn2+Fe43+(PO4)3(OH)5) might be a possibility. For frondelite the ratio is 3:4:1. Moreover, frondelite can sometimes be blue. But it doesn’t look like vivianite. Does frondelite form PSMs after vivianite? I have no idea. But vivianite (Fe32+(PO4)2 • 8H2O) is not a good fit for scan #162. There is almost no Mn in vivianite (and not much in metavivianite). So I think a PSM of some sort is likely. I posted many stereo child photos of these "crystals" - all as unidentified.

In addition, there is a large area covered by dark green platy/scaly looking stuff. I expected it to be a mica or chlorite, but scan #164 doesn’t match anything that I know. (The scan looks as if all the P in rockbridegeite had been replaced by Al and Si.) This is also posted as unidentified.

The full-view photo shows all of the minerals except the weird UK: huereaulite on the right, dark green manganoan rockbridgeite in the center, and the putative PSM after vivianite on the left. The latter consists of microcrystals in small cavities and as an encrustation on quartz. Most of it is actually on the "bottom". It looks more indigo tahn blue in the photo, but mostly pale blue under a scope. A few crystal look deep blue and gemmy - as if unaltered.

The strange UK is a crust on quartz on the “back”.
Photo ID: 857250     Uploaded by: Modris Baum   View Count: 36   Approval status: Public galleries    Type: Photo - 4080 x 3296 pixels (13.4 Mpix)

RH5-DF9Xenotime-(Y) : YPO4

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 0.85 mm
Largest Crystal Size: 0.25 mm

THis is a very tiny crystal. Because of the dark color, it was suspected to be a "stretched" or distorted anatase bi-pyramid. However, qualiative EDS says that it is xenotime-(Y). See the analysis child "photo" for a full discussion.
Photo ID: 856041     Uploaded by: Modris Baum   View Count: 16   Approval status: Public galleries    Type: Photo - 2076 x 2262 pixels (4.7 Mpix)

DMF-H0VAdamsite-(Y) : NaY(CO3)2·6H2O

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 6.8 mm

Adamsite-(Y) replacing shomiokite-(Y). There is a bit of basntnäsite-(Ce) on the right end.

A sample of the basntnäsite was analyzed via qualitative EDS, but the sample had adhering adamsite and was crushed in the mail. The resulting scan shows a mixture of adamsite and basntnäsite. See the analysis child photo. It is not clear if there is any relict shomiokite-(Y), but morphology clearly suggests that it was the precursor.

This is part of a very complex specimen that also has weird "sausages" of variable, intermediate, parisite-(Ce), synchysite-(Ce), and donnayite-(Y) compositon. See the child photos.

Some of the "sausages" are encrusted by tiny hexagonal saucers of a zeolite, probably chabazite-Na. See the corresponding child photo.

In addition, there is smoky quartz, siderite, epididymite and eudidymite. The latter were also analyzed, but I did not post photos or scans because the eudidymite is similar to [https://www.mindat.org/photo-430051.html], which is probably from the same find. (The EDS scans are not much to look at. They just show Si and Na, since Be can't be detected.)
Photo ID: 855395     Uploaded by: Modris Baum   View Count: 18   Approval status: Public galleries    Type: Photo - 1024 x 687 pixels (0.7 Mpix)

Q2E-VARSteacyite : K0.3(Na,Ca)2ThSi8O20

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 1.4 mm
Largest Crystal Size: 0.35 mm

MSH is the TL for steacyte. Brown cruciform twins, characteristic of MSH, are probably the best know. There are several other, very uncommon, habits here. But the closely packed, radiating, habit on this specimen is unique in my experience. Remarkable adiating spays of – colorless! - steacyite are known from Água de Pau, but not from MSH. It was a great surprise when EDS said “steacyite”. See the analysis child "photo" for details.

These are very small crystals. In this view, the entire aggregate spans < 1.5 mm. A very rough estimate of the lenght of indiviual prisms is <= 0.35 mm. The most robust cross-sections (including the somewhat "frizzy" looking "rind") are < 0.05 mm. Such objects are really beyond the capabilities of my scope, so the photo is rather blurry - even after stacking. Nonetheless, the squarish cross sections of some of the prisms can be seen faily well. (The external "rind" gives some of the prisms a rounded appearance.)

The steacyite aggregates are associated with eudidymite (or perhaps epididymite). In my experience, that too is a unique combination. There is only a small bit of matrix, so it is hard to say what the environment is. Possibly breccia or brecciated hornfels.

Stereo child photos show this and another steacyte aggregate as well a some of the eu/epididymite.
Photo ID: 854399     Uploaded by: Modris Baum   View Count: 19   Approval status: Public galleries    Type: Photo - 795 x 1024 pixels (0.8 Mpix)

TQR-ELTBaryte : BaSO4, Strontianite : SrCO3

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Dimensions: 85 mm x 65 mm x 45 mm
Field of View: 2.3 mm
Largest Crystal Size: 1.5 mm
Weight: 250 g

The baryte crystals are <= 1.5 mm long. The "spiky" strontianite ball is about the same size.

Baryte is a rare mineral at MSH. This is a very nice example from hornfels. The associated strontianite is somewhat more common, but this is an exceptionally rich specimen for the locality. There are also some small smoky quartz crystals (see the child photos).

Just to be sure (given the rarity of baryte at MSH), the baryte was confirmed via EDS. See the analysis "photo".
Photo ID: 854071     Uploaded by: Modris Baum   View Count: 11   Approval status: Public galleries    Type: Photo - 3104 x 4507 pixels (14.0 Mpix)

MEL-PDTFaujasite-Na : (Na,Ca,Mg)2(Si,Al)12O24·15H2O

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 2.35 mm

The longest edges on the main crystal are 0.9 mm.

This specimen has not been analyzed, but it is almost undoubtedly from the same find as [https://www.mindat.org/photo-170873.html], which is from the first (and only) fully verified find of faujasite-Na at MSH. (A few other specimens have been found, but they are from the same area and were made at about the same time.)

The faujasite on this specimen was noticed only recently (Oct 2017) when doing a careful examination of "left-overs" from this time period. The little box contining this (and several other fragments without faujasite) was labeled as having been collected about a month after the fully verified specimens, but the matrix, association, and appearance are the same. Note in particular the twinning, especially on the left and on the "base". This sort of twinning appears to be characyteristic of faujasite-Na at MSH.

There are a few child photos (some in stereo) with slightly diffrent views.
Photo ID: 853360     Uploaded by: Modris Baum   View Count: 16   Approval status: Public galleries    Type: Photo - 1024 x 908 pixels (0.9 Mpix)

28A-139Corundum : Al2O3

Multiple photos available
Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada

Field of View: 2.05 mm
Largest Crystal Size: 0.75 mm

As corundum goes, this is – ahem - “less than impressive”. In fact I didn’t believe the allegation, so I had it analyzed via EDS – which said “corundum”. (See the “Analysis” photo). Corundum is a very rare mineral at MSH, but even here, there are probably better examples. Howeve, this one has been analyzed, and perhaps worth posting for that reason.

I tried using different lighting in two versions of ths photo (see one of the child photos for the other version). But I can’t say that either photo manages to make the corundum (0.75 mm) look like corundum. What else lives at MSH and consists only of Al and elements lighter than Na? Only the Al hydroxides such as gibbsite et al. Clearly, this isn’t one of those.
Photo ID: 850727     Uploaded by: Modris Baum   View Count: 16   Approval status: Public galleries    Type: Photo - 2802 x 2448 pixels (6.9 Mpix)
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