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Small specimen of fluorite formed by a group of colorless crystals, translucent, dull and showing forms of the cube and the dodecahedron. A representative miniature.
Very esthetic group of fluorite crystals, very transparent, with brilliance and very sharp faces and edges, showing forms the cube with the dodecahedron and small trapezohedron. Violet tone color zoning. From a classic locality.
An aesthetic specimen of twinned cassiterite crystals, lustrous, striated, deep black very aerial disposed on a schist matrix with muscovite plates. This excellent piece is from a classic Spanish locality for cassiterite.
Group of datolite crystals, very rich in faces, translucent-white and well defined. They are on a matrix with calcite and quartz, with some epidote-clinozoisite. A piece of a well-known Spanish quarry from where nowadays is very difficult obtain samples because they are not making new blastings.
A rich group of scalenohedral calcite crystals showing parallel growth, with very sharp faces and edges. They are peppered by small crystals of chalcopyrite. They are accompanied by groups of brilliant fluorite crystals, with transparence, bluish tones and cubic forms truncated by the dodecahedron.
They are well known yellow and colorless fluorite specimens from Matagalls (Sant Marçal) mines in the Montseny massif. But less common are these fluorite with blue to green tones (depending on the type of incident light). They show crystals cubic with defined faces and edges, good brilliance and transparence. They are accompanied by small aggregates of hyaline quartz. A historical piece.
Fragment of a calcite vein that presents a more rich cobaltoan area which gives this pink tone. An old specimen (ca. 1980) that deserves our attention. From a classic Catalan mine.
This specimen is from my old field trips to the El Molar (Tarragona) area. In this sample we combine rhodonite (more granular appearance, crystalline) with pyroxmangite (more compact appearance). Accompanied by black veins of todorokite. The tephroite, scarce, appears as patches of brownish tone in the manganese oxydes. These differentiations rhodonite-pyroxmangite are indicative, both minerals usually appear mixed.
It is an old mine we call generically as Serrana mine, although in fact there are two different mines, with two separate dumps, one corresponding to the actual Serrana mine (with horizontal works), while the other (closest to the river and with vertical works) would be known as Manganese mine.
This specimen is from my old field trips to the El Molar (Tarragona) area. In this sample we combine rhodonite (more granular appearance, crystalline) with pyroxmangite (more compact appearance). Accompanied by black veins of todorokite. The tephroite, scarce, appears as patches of brownish tone. These differentiations rhodonite-pyroxmangite are indicative, both minerals usually appear mixed.
It is an old mine we call generically as Serrana mine, although in fact there are two different mines, with two separate dumps, one corresponding to the actual Serrana mine (with horizontal works), while the other (closest to the river and with vertical works) would be known as Manganese mine.
This is a specimen of tabular barite crystals, colorless to yellowish tones and very good transparence. With minor marcassite on matrix. Stable till 1990's. These specimens are uncommon in the market. It comes from the former Daunis (Barcelona) collection. A piece with history.
In the matrix of goethite we observe several cavities covered by small brilliant crystals, gray metallic luster; once analyzed results indicated to be hydrohetaerolite. We discuss whether it is hetaerolita, but analysis carried by Joan Viñals indicated the hydrated form. Under the SEM-EDS, tetragonal dipyramids are observed. It is accompanied by calcite crystals and hemimorphite (tabular crystals in book shape). SEM-EDS analysis will be sent to buyer.
A good size crystal of teruelite, a variety of dolomite, from the Valencian cut in the CV-35 road well known for these sized specimens. The crystal shows the rhombohedron, brown and translucent under the light. It is included in a solid matrix of gypsum.
A very rich group of prismatic crystals, some almost acicular, of brochantite with an intense green colour and good brilliance and transparence. Nice to be displayed and enjoyed under magnifying glass. Disposed in the baryte cavities. SEM-EDS analysis results will be sent to the buyer.
A very rich group of prismatic crystals, some almost acicular, of brochantite with an intense green colour and good brilliance and transparence. Accompanied by groups of atacamite crystals with tabular shape and thicker prism, with a deep green color and transparence, easy to distinguish. Nice to be displayed and enjoyed under magnifying glass. SEM-EDS analysis results will be sent to the buyer.
Very rich druse of hyaline quartz crystals from a not very-known Spanish locality. Brilliant short prisms, with rich parallel growth, and nice terminal faces. With well defined faces and edges. From its quarries various rock typologies are extracted, the main and the most abundant is the granite characterized by its high hardness and quality, which was honored with a denomination itself, Grey Villa Granite.
Excellent sphalerite miniature from this Basque classic mine. It shows a group of brilliant crystals, with a good size, defined faces and slightly curved edges. Good transparence with dark toasted honey-colored tones. Troya mine was closed in 1993, only a few years before these specimens were collected in 1990. Nowadays the mine is collapsed and flooded.
Large group of sphalerite crystals with an exceptional brilliance, honey color and transparency that allows light to play with the honey colors. Peppered by small crystals of calcite showing flattened shapes of the rhombohedral and prism. A little gemmy miniature. Troya mine was closed in 1993, only a few years before these specimens were collected in 1990. Nowadays the mine is collapsed and flooded.
Aesthetic specimen of this classic Basque mine that shows a matrix with numerous small sphalerite crystals, honey to orange color, transparent and brilliant. Partially covered by groups of rhombohedral siderite with a staggered growth. With good size, slightly curved faces and edges and very characteristic green color. A very aesthetic specimen.
Troya mine was closed in 1993, only a few years before these specimens were collected in 1990. Nowadays the mine is collapsed and flooded.
From a classic Murcian loocality as corta San Valentín comes this specimen formed by a large group of bright sphalerite crystals with tetrahedral and complex shapes, good brightness and partially covered bu lenticular and rhombohedral orange siderite crystals. A very aesthetically striking contrast color.
Group of very sharp trapezohedral analcime crystals, good brilliance and with the usual transparency for the species. They are disposed in a cavity of the volcanic rock covered by calcite. Very interesting specimen from a poorly represented locality in collections.
These specimens have given more than a headache. They have sometimes been cited as celestine from Moscona mine. This specimen shows a group of barite prismatic crystals very rich in faces, with the combination of various orthorhombic prisms and pinacoids. Transparency is excellent and with an amazing brilliance. They are disposed in a matrix with white crystals of calcite. Very few specimens in collections.
Analysis and article in our blog:
Group of rhombohedral calcite crystals with a complex combination showing defined faces and rounded edges. Translucent and very curious waxy luster. On them various prehnite globular aggregates formed by radial growths. A very unusual mineralogical curiosity.
A very aesthetic specimen formed by a large group of silver crystals and filaments, forming spongy and skeletal growths. Good luster and a slightly tan tone. Stresses this specimen by several factors. One is its size and weight (on 40 g. or 1.4 oz.). Another is the abundance of this noble metal and perhaps the most interesting is that it is not an acidified sample. This is a plate obtained from a natural fissure in the host rock, with a lenticular and flattened structure. A very different piece from this classic Catalan locality.
This specimen shows one way how silver occurs in Balcoll mine. We note that into the fissures in the limestone have grown numerous skeletal aggregates formed by silver crystals showing well defined forms of the octahedron. Good luster and a bronze patina tone. Accompanied by groups of cubic crystals of acanthite with staggered growths and deep black color. A very representative sample from a classic locality for the Catalan mineralogy.
A very aesthetic specimen formed by several groups of cubic silver crystals with a skeletal shape. They show defined octahedral and cubic faces. The color varies from white to bronze. Accompanied by acanthite aggregates with a darker color. These specimens come from a classic Catalan locality for the species.