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Calcites from Grabiszyce Quarry, Poland
Calcites from Grabiszyce Quarry, Leśna, by Tomasz Praszkier
INTRODUCTION and HISTORY LOCATION
Satellite photo of Earth with marked area that is shown in the next figure.
Map of Poland with Grabiszyce area marked, and close-up of south-western Poland.
Map of the quarry vicinity; yellow line marks the borderline with the Czech Republik.
Aerial view to the quarry. T. Praszkier photo.
Aerial view to the quarry. T. Praszkier photo.
Aerial view to the quarry. T. Praszkier photo.
Grabiszyce Quarry. J. Praszkier photo.
Drone footage of the quarry and its surroundings. J. & T. Praszkier movie.
GEOLOGY and SPECIMENS
The Grabiszyce quarry is located in the Karkonosze-lzera Block geological unite, which is a part of the Sudetes Mts. Alkaline basalts mined in the quarry are part of a bigger volcanic province spread around Lubań. They were exploited from the XIII century for the construction purposes.
Sattelite photo of the quarry with the volcanic neck called "Stożek Perkuna" marked.
Two lava flows interbedded by continental sands visible in the quarry. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Breccia zone rich in calcite mineralization. J. Praszkier photo.
Breccia zone rich in calcite mineralization. J. Praszkier photo.
Tom in front of the breccia zone. J. Praszkier photo.
Numerous calcite pockets in the breccia zone. J. Praszkier photo.
Numerous calcite pockets in the breccia zone. J. Praszkier photo.
Freshly opened calcite pocket. J. Praszkier photo.
Specimens from the breccia zone were generally extracted in smaller sizes because the basalt there was partly decomposed and easily split into smaller fragments. Specimens from better pockets were collected as fragments as big as possible, and trimmed later. After preparation the majority of the specimens became relatively small, usually between 3-10 cm. There was only a dozen of specimens above 15 cm. The most attractive, intensively orange clusters were quite rare. Most of the specimens are flat, only small percentage has rosettes of crystals or other interesting shapes. Luster on most of the specimens is good. Looking on general quality only a few dozens of specimens, from hundreds, is good quality.
Collecting in the breccia zone. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Collecting in the breccia zone. J. Praszkier photo.
Freshly collected calcite specimen. J. Praszkier photo.
Freshly collected calcite specimen. J. Praszkier photo.
This is how the specimens look like before the preparation, they need a lot of trimming. T. Praszkier photo.
This is how the specimens look like before the preparation, they need a lot of trimming. T. Praszkier photo.
Calcites from the breccia zone after cleaning and trimming. Spirifer specimens. J. Praszkier photo.
Calcite specimen from the breccia zone, size 10 cm. Spirifer specimen. J. Praszkier photo.
Rosettes of deep orange calcite from the breccia zone, size 8 cm. Spirifer specimen. J. Praszkier photo.
Rosettes of deep orange calcite from the breccia zone, size 9 cm. Spirifer specimen. J. Praszkier photo.
Rosettes of deep orange calcite from the breccia zone, size 9 cm. Spirifer collection. J. Praszkier photo.
Intensively orange calcite, size 10 cm. M. Oleszczuk specimen. J. Scovil photo.
Calcite specimen with interesting morphology, size 14 cm. Spirifer collection. J. Callen photo.
Calcite, size 10 cm. Spirifer collection. J. Callen photo.
The second productive zone is located in the upper part of the main quarry level, on the top of the lower lava flow. J. Praszkier photo.
The second productive zone is located above the basalt pillars, in the upper part of the quarry level. J. Praszkier photo.
Collecting specimens from the second productive zone. They are found there as big basalt blocks that have fallen down from the top of the wall. Their original source is located above the basalt pillars. J. Praszkier photo.
The only way to extract calcites from the big blocks of massive basalt is to cut them off with a diamond saw. P. Lejczak photo.
Very rarely specimens in that zone are found like this one - as loose small floaters. Calcite on bluish ferrosaponite. Size 6.5 cm. M. Oleszczuk specimen. T. Praszkier photo.
Rare, high quality specimen of constractive calcites on ferrosaponite. Size 10 cm. Spirifer collection. J. Callen photo.
The only specimen of calcite "ball" perched on the top of basalt coated with ferrosaponite, complete all around. Size 5 cm. Spirifer collection. J. Callen photo.
Yellow calcite crystals on ferrosaponite. Size 8.5 cm. Spirifer collection. J. Praszkier photo.
Complex calcite crystals on black ferrosaponite. Size of calcite aggregates 2.5 cm. Spirifer collection. J. Callen photo.
One of the best specimens found as far in the second productive zone. Size 17 cm. Spirifer collection. T. Praszkier photo.
MINERALS
Calcite is obviously the most important mineral species in Grabiszyce. Its general characteristics is very different in both zones described above.
Typical pocket in the berccia zone with the walls coated with a "carpet" of orange calcite. J. Praszkier photo.
Fragment of the calcite pocket from breccia zone, coated with a "carpet" of the steep rhombohedral crystals. Size 17 cm. K. Tekiela collection. J. Callen photo.
Close up of the rosette of calcite rhombohedral crystals, typical for the breccia zone. Size of the rosette is 2 cm. J. Callen photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. FOV 7 cm. P. Lejczak collection. J. Praszkier photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. Size 11 cm. K. Tekiela collection. J. Callen photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres."Ball" size 2.5 cm. Spirifer collection. J. Callen photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. "Ball" size 2.5 cm. Spirifer collection. J. Callen photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. Crystal size 2 cm. K. Tekiela collection. J. Callen photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. FOV 8 cm. Spirifer collection. J. Scovil photo.
Series of photos showing the continuity of calcite forms; all of them are complex aggregates of macromosaic rhombohedra with different morphologies depending on the degree of curving of rhombohedron edges - from those with rhombohedron faces well visible to the “botryoidal like” aggregates that look like spheres. Size 6.3 cm. M. Oleszczuk collection. J. Scovil photo.
“Mercedes emblem” - distinctive feature of the “botryoidal like” aggregates. These are traces of the rhobohedron terminations which are completely covered by extremely curved and bent peripheral parts of the aggregates. Close-up of the previous photo.
Complex calcite aggregates with splitted and shifted steep rhombohedron forms. FOV 6 cm. K. Tekiela collection. J. Callen photo.
Complex calcite aggregates with splitted and shifted steep rhombohedron forms. Size 9.5 cm. Spirifer collection. J. Scovi photo.
Complex calcite aggregates with spheroidal central part and splitted and shifted steep rhombohedal terminations on both ends. FOV 9 cm. K. Tekiela collection. J. Callen photo.
Complex calcite aggregates in "bow tie" forms featuring splitted and shifted steep rhombohedron forms. Size 6 cm. M. Oleszczuk collection. J. Callen photo.
Complex calcite aggregates in "bow tie" forms featuring splitted and shifted steep rhombohedron forms. Size 7 cm. Spirifer collection. J. Praszkier photo.
Ferrosaponite is a clay mineral, very rarely being part of the mineral specimens in general. In Grabiszyce it occurs in the zone on the top of the lava flow. It is developed as thin globular layer covering pockets walls. Color of the surface is usually black or grey, but in some pockets, can be blue or even iridescent with rainbow colors.
Coatings of the blue ferrosaponite around the calcite pocket, in situ. J. Praszkier photo.
Coatings of the bluish ferrosaponite with spheroidal calcites. J. Praszkier photo.
Globular iridescent ferrosaponite with spheroidal calcite, size 6 cm. Spirifer collection. J. Scovil photo.
Gemmy and lustrous phillipsite crystals on black ferrosaponite with spheroidal calcite, size 7 cm. Spirifer collection. J. Callen photo.
Close up of the phillipsite on the specimen pictured above, FOV about 3 cm. Spirifer collection. J. Callen photo.
Pyrite spheroidal aggregates on basalt. J. Praszkier photo.
FUTURE PERSPECTIVES
Grabiszyce quarry has almost reached the limits of mining claim, and if expanding the claim will be possible is unknown at the moment. Brecciated zone with orange calcites is almost completely extracted, so the only remaining productive area is the zone on the top of the lava flow.
Acknowledgments We would like to thank prof John Rakovan for his help with editing this article.
See specimens from Grabiszyce in our store
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