Frédéric Messier Leroux's Photo Gallery
7FA-JJGCalcite CaCO3
Dimensions: 11.2 cm x 7.7 cm x 4.8 cm
Cabinet-sized calcite crystals plate, with very interesting zoned fluorescence. Its brightest response is seen under longwave UV / UV-A (shown in the main picture), followed by midwave UV / UV-B (photo #2). The shortwave UV / UV-C response (photo #3) is the weakest.
This specimen is the brightest of the three specimens from this locality in my collection.
Shown in visible light in the last photo.
H38-W88Calcite CaCO3
Dimensions: 23.8 cm x 10.2 cm x 5.8 cm
Large plate of calcite crystals, with very interesting zoned fluorescence. Its brightest response is seen under longwave UV / UV-A (shown in the main picture), followed by midwave UV / UV-B (photo #2). The shortwave UV / UV-C response (photo #3) is very dim.
Shown in visible light in the last photo.
Mindat.org Photo of the Day - 13th Dec 2023
RQ7-7Y1Calcite CaCO3
Dimensions: 6.2 cm x 5.2 cm x 3.8 cm
Calcite crystal, from the La Sambre quarry. It fluoresces rather dimly, but shows a different response under each UV wavelength.
Of interest is a very small area on one of the tips of the crystal, which shows a reaction comparable to "Terlingua-Type calcite" (blue fluorescence under shortwave UV / UV-C, and long-lasting and bright blue phosphorescence upon exposure to SW, and bright pink fluorescence under longwave UV / UV-A).
Shown, respectively: Shortwave UV (255 nm UV-C LED), SW UV phosphorescence/"afterglow", midwave UV / UV-B (310 nm UV-B LED), longwave UV, and visible light.
2D5-KNDCalcite CaCO3
Dimensions: 10.2 cm x 8.1 cm x 4 cm
Shown here is a very nice specimen of Terlingua calcite, with a few unusual features. First, it is a single cleaved mass with a large and well-defined cleavage plane, unlike most of the calcite from this locality which tends to be more granular. The person from whom I got this specimen told me this is one of the best cleavages he's seen in this material, and he handled a lot of it over many years.
Another rather unusual characteristic is that along with the typical blue fluorescence this material shows under shortwave UV / UV-C (shown in the main picture and in picture #7), atypical pinkish lavender hues are also present; and small spots on the back of the specimen, shown in photo #7, fluoresce lavender. Also, the longwave UV / UV-A fluorescence of the front side (photo #4) is redder than the usual pink response seen under LW.
The back side of the specimen shows an even more unusual response under LW (photo #9); along with the typical pink, reddish pink, lavender and peach tones are also present. I made sure that the color rendition is accurate, by comparing the specimen side-by-side with the photos on my computer monitor.
The specimen is shown under shortwave UV in the first and 7th pictures, the SW UV phosphorescence/"afterglow" is shown in the second picture. Midwave UV / UV-B (306 nm) is shown in photo #3 and photo #8; in the fifth picture, the front side of the specimen is shown fluorescing in blue light (450 nm), and it is shown in visible light in photos #6 and 10.
C13-XD5Calcite CaCO3
Dimensions: 9.5 cm x 6.4 cm x 6 cm
Nice specimen of typical Terlingua calcite, with the sought-after triangular zones of bright fluorescence. Shown fluorescing under shortwave UV / UV-C in the main picture; then, in the next photos are shown, respectively: SW UV phosphorescence/"afterglow", midwave UV / UV-B fluorescence, longwave UV / UV-A fluorescence and then the specimen is shown in white light in the last image.
PEH-JPGBaryte BaSO4 , Calcite CaCO3
Dimensions: 7 cm x 3.1 cm x 3 cm
The Meloche quarry is generally not known as a fluorescent minerals locality; most stuff found there does not react to UV. This piece, consisting of stalactitic baryte covered with some yellow "dogtooth" calcite crystals, is one of the rare ones that do.
Under midwave UV/UV-B (shown in the main image, and in photo #3), the calcite fluoresces a moderately bright pink, and the baryte fluoresces orange. The baryte seems to consist of three successive generations; the first generation being thin stalactitic opaque white baryte, covered by a second generation of slightly transluscent baryte which fluoresces orange under UV-B, and a thin third generation that partially covers the fluorescent baryte, which shows up only where the last generation material is absent, and in the broken base of the "stalactite", which is shown in the last picture. In daylight, the non fluorescent baryte is pure white, and the fluorescent baryte is cream colored.
The specimen is shown in visible light in photos #2 & #4.
Self-collected in 2017, from a pocket I called the "White clouds pocket", due to the abundance of botryoidal white baryte clusters resembling clouds that I found in it, along with stalactitic baryte and calcite crystals and some marcasite. This pocket, which luckily I had the time to fully work after finding and opening it, was in an area that has since then been blasted away. Access was granted only in weekends so I consider myself lucky to have had just enough time to recover the entirety of the pocket before the area was blasted!
Access to this quarry used to be easy until recent years, but someone got caught trespassing at night, which resulted in the quarry owners deciding to not grant access to collectors like before.
24V-P73Marcasite FeS2 , Baryte BaSO4 , Calcite CaCO3
Dimensions: 10.7 cm x 6.6 cm x 2.3 cm
Botryoidal marcasite with multicolor iridescence, associated with some white baryte rosettes, covered with tiny grey calcite crystals. It comes from a big pocket I discovered and fully worked in 2018, shortly before the quarry owners stopped granting access to collectors on weekends like they used to, after someone was caught trespassing at night. Fortunately enough, I had just enough time to finish the pocket before the area it was in was blasted away. It wasn't the case with all pockets I found there; in some cases I had just enough time to start working the pocket but it was gone the next weekend.
This one, which I nicknamed the "Rainbow pocket", due to the fact that all the marcasite it contained displayed impressive iridescent colors, which was not always the case in other pockets, was undoubtedly the best pocket I've ever found there, and also the largest. Other pockets almost always contained nice specimens (except two which contained only small greyish "dogtooth" calcite crystals), but this one contained almost only high quality, very aesthetic, and oftenly quite large specimens. Stalactitic and botryoidal white baryte were also found in this pocket; some weird hollow baryte crystals, sometimes in stalactitic clusters, were also found. One of these specimen contained a very slender and thin marcasite stalactite, and some white powdery material.
This is one of only a few botryoidal marcasite specimens I recovered from this pocket; most marcasite in it was "stalactitic" instead of botryoidal.
ARU-1WVMarcasite FeS2 , Baryte BaSO4 , Calcite CaCO3
Dimensions: 11.7 cm x 8.1 cm x 2.8 cm
Botryoidal marcasite with beautiful blue and golden iridescence, associated with some white baryte and tiny grey calcite crystals, from a big pocket I discovered and fully worked in 2018, shortly before the quarry owners stopped granting access to collectors on weekends like they used to, after someone was caught trespassing at night. Fortunately enough, I had just enough time to finish the pocket before the area it was in was blasted away. It wasn't the case with all pockets I found there; in some cases I had just enough time to start working the pocket but it was gone the next weekend.
This one, which I nicknamed the "Rainbow pocket", due to the fact that all the marcasite it contained displayed impressive iridescent colors, which was not always the case in other pockets, was undoubtedly the best pocket I've ever found there, and also the largest. Other pockets almost always contained nice specimens (except two which contained only small greyish "dogtooth" calcite crystals), but this one contained almost only high quality, very aesthetic, and oftenly quite large specimens. Stalactitic and botryoidal white baryte were also found in this pocket; some weird hollow baryte crystals, sometimes in stalactitic clusters, were also found. One of these specimen contained a very slender and thin marcasite stalactite, and some white powdery material.
This is one of only a few botryoidal marcasite specimens I recovered from this pocket; most marcasite in it was "stalactitic" instead of botryoidal.
52C-9PRBaryte BaSO4
Dimensions: 6.3 cm x 5.4 cm x 3.9 cm
Cute little specimen, consisting of a "stalactite" of white baryte crystals, standing vertically on a flat matrix consisting of tiny white baryte crystals. I found this specimen in late 2017, in one of the smallest baryte pockets I've worked in this quarry. Since most of the specimens that came from this pocket consisted of flower-like clusters of white baryte crystals on matrix, I nicknamed it the "White flowers pocket". This specimen is my favorite among those I recovered from this rather small pocket.
It was far from being the most impressive and productive pocket I found there, but the specimens that came out of it were quite lovely. Due to its small size, I fully worked this pocket in just a matter of a few hours, while most pockets took at least one full weekend of work from early morning to dusk, and in some cases 2-3 weekends in a row.
EP9-MEJBaryte BaSO4
Dimensions: 5.8 cm x 4.5 cm x 1.6 cm
Cute little specimen, consisting of flower-like groupings of white baryte crystals, on a flat matrix consisting of tiny white baryte crystals. I found this specimen in late 2017, in one of the smallest baryte pockets I've worked in this quarry. Since most of the specimens that came from this pocket were comparable to this one, I nicknamed it the "White flowers pocket".
It was far from being the most impressive and productive pocket I found there, but the specimens that came out of it were quite lovely. Due to its small size, I fully worked this pocket in just a matter of a few hours, while most pockets took at least one full weekend of work from early morning to dusk, and in some cases 2-3 weekends in a row.
