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Recently, specimens of scapolite of Moroccan origin have appeared on the market. The analyses we have carried out on several specimens indicate that it is mainly marialite, since the proportion of Na (marialite, Na₄Al₃Si₉O₂₄Cl) is higher than that of calcium (meionite, Ca₄Al₆Si₆O₂₄CO₃), and the presence of chlorine is also detected. We can see that the proportion of Ca is quite high, so we are in the middle of the marialite-meionite series. Crystals appear as tetragonal prisms truncated by the basal pinacoid and the first-order dipyramid. Transparent to translucent and with some inclusions. Fluorescent under SW-UL. We will send the analyses to the buyer.
Recently, specimens of scapolite of Moroccan origin have appeared on the market. The analyses we have carried out on several specimens indicate that it is mainly marialite, since the proportion of Na (marialite, Na₄Al₃Si₉O₂₄Cl) is higher than that of calcium (meionite, Ca₄Al₆Si₆O₂₄CO₃), and the presence of chlorine is also detected. We can see that the proportion of Ca is quite high, so we are in the middle of the marialite-meionite series. Crystals appear as tetragonal prisms truncated by the basal pinacoid and the first-order dipyramid. Transparent to translucent and with some inclusions. Fluorescent under SW-UL. We will send the analyses to the buyer.
Group of pentadodecahedral pyrite crystals on a matrix with small quartz and tennantite crystals. Pyrite shows striated faces and an exceptional luster. In some of the pentadodecahedral pyrite crystals, we can observe edges truncated by the cube faces and some vertices by the octahedron.
These selenite gypsum specimens show the "swallow tail" and reverse twinning. They show a certain transparence, which allows us to see the inclusions, and a good brilliance due to the natural polishing of the gypsum. The most interesting thing, in my opinion, is this rounded appearance due to the erosive action of the sea spray, since they appear in the clays of the Eocene cliffs. A very English curiosity from Jaime Murria's collection.
Very aerial topaz crystal on a matrix of quartz and albite. The crystal has well-developed prism faces truncated by the faces of the dipyramids, with excellent transparency, uniform honey color and good luster. It has a small chip on the top back without affecting the quality.
Specimen formed by interpenetrating cubic fluorite crystals that show well-defined cube faces and bevelled edges, with stepped and tile-like growths. With good luster, transparency and marked geometric colour zoning, ranging from sky blue inside the crystals to violet blue on the outside (very intense on some edges).
Specimen of fluorapatite from the famous Cerro de Mercado mine in Mexico. The main crystal is prismatic, terminating in the faces of the hexagonal dipyramid. The luster and transparency are excellent and the color is very intense greenish yellow. It is arranged on a calcite matrix containing elongated augite crystals.
Specimen of fluorapatite from the famous Cerro de Mercado mine in Mexico. It is presented as a prismatic crystal terminated by the faces of hexagonal dipyramids. The transparency and brilliance are excellent and the color is very intense yellow. It is arranged on a matrix containing hematite and small augite crystals.
Very good sized fluorapophyllite-(K) crystal. It shows prism faces truncated by the dipyramid. Very bright, transparent to translucent. On matrix with stilbite-Ca. A classic from India.
A very brilliant group of epidote crystals with an intense and deep green color. It shows a very rare habit for the species. We can observe psedo-octahedrical forms in one side and a flattened shape generated by a extremely developed frontal pinacoid. To increase its scientific interest we must say that it is magnetic due to magnetite inclusions.
Excellent specimen of bournonite from this classic Kosovar mine. Several crystals of this lead and copper sulfoantimonide are disposed on a matrix formed by brilliant crystals of pyrite, sphalerite and galena. The bournonite presents visible cyclic twins, semi-matt luster, with chalcopyrite.
A very good-sized specimen with an aggregate of brilliant aegirine crystals of an intense green, almost black colour, with well-defined faces and edges. It is accompanied by green fibrous crystals of arfvedsonite. They are disposed in a matrix of orthoclase crystals with quartz.
Specimen of purpurite with an intense violet colour. It is accompanied by other phosphates. In the words of Antonio Manuel Inácio Martins: -"Purpurite is lilac, triphylite is brown, rockbridgeite is green dark and stewartite is yellowed... crazy phosphates". Enjoy the sample.
Malachite specimens from this Upper Katanga mine are notable for radial aggregates of fine crystals that, taken together, have a velvety appearance and excellent brilliance. Intense green colour, good size and fine aesthetics.
Malachite specimens from this Upper Katanga mine are notable for radial aggregates of fine crystals that, taken together, have a velvety appearance and excellent brilliance. Intense green colour, good size and fine aesthetics.
Malachite specimens from this Upper Katanga mine are notable for radial aggregates of fine crystals that, taken together, have a velvety appearance and excellent brilliance. Intense green colour, good size and fine aesthetics.
Numerous rhodochrosite crystals are disposed on a druse of quartz crystals, defined, transparent to translucent. They present a very remarkable richness of faces, to be enjoyed under magnification, highlighting numerous reflection twins, with dull faces and bright faces alternating by geometry. A very aesthetic curiosity.
A large group of rhodochrosite crystals, with pointed scalenohedron shapes but with striated faces and a very aesthetic pearly luster. The pink-red colour is more intense inside the crystals. It seems that a second generation of rhodochrosite has covered the primary crystals. It is accompanied by crystals of hyaline quartz, together with colourless, well-defined fluorite cubes with opaline faces, except at the vertices, a curious geometry. Aesthetic piece.
An excellent specimen of quartz, with a slight smoky tone, which presents very aesthetic "window" geometric growths. Doubly terminated and with complex crystallography. With inclusions.
The first specimens were found in the mines of Aït-Ahmane between 2014 and 2015. The best ones reached the market around 2017. They are twinned crystals of remarkable perfection for the species, formed by intergrowths of djurleite and chalcocite. No better specimens have been found in the area and probably worldwide.
Although some relatively recent analytical results (see mindat) indicated that they were crystals of djurleite only, others indicated that they were mixtures of both species. Realistically, djurleite and chalcocite often appear together in the same crystal, and one can even transform into the other depending on the physical-chemical conditions present. For this reason I have preferred to preserve the name of both species. Interesting article: Pósfai-Buseck Amer. Min. 1994.
A very faceted tabular crystal of wulfenite. It stands out for its deep blue colour, which is unusual for this species. It belongs from the Bou Skour mine, where crystals of this type have been obtained, but they are usually very small, around a millimetre. This one measures 8 mm...
Group of sphalerite crystals with parallel and polycrystalline growths, slightly curved on the faces and edges, transparent to translucent and shiny. When exposed to light from behind, it takes on a honeyed to greenish tone.
Floating specimen of copper, formed by dendritic to arborescent aggregates of copper crystals.
Native copper specimen formed by various rounded and flattened copper crystals, in arborescent to dendritic growths. It is accompanied by a minor quartz matrix.
Native copper specimen formed by various rounded copper crystals, in arborescent to dendritic growths.