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A great sample of arsenopyrite, pale gold to silver in colour with slight iridenscence and a bright metallic lustre, with several intergrown crystals all showing complex striations and serated crystal edges. Accompanied by black ferberite. Good sized and fine specimen.
Group of ferberite crystals of very good size, exceptional luster and well defined faces and edges. From this classic Portuguese mine. It belongs to the Arguijo collection.
From specimens like these, this very rare species was identified: panasqueiraite. Identifying it in each sample is an almost impossible task. Panasqueiraite is a monoclinic calcium-magnesium phosphate, it would be an hydroxylated analog of isokite. In Panasqueira, its type locality, it is found as massive fine-grained aggregates together with other phosphates (fluorapatite, thadeuite, wolfeite, triplite, althausite and vivianite), with topaz, quartz and sulfides (arsenopyrite, pyrrhotite, chalcopyrite and sphalerite) in veins hydrothermal. The panasqueiraíta closely resembles the thadeuíta and the wolfeíta, but with the naked eye the three species can be distinguished by their slightly different colors: thadeuite: yellow-orange; wolfeite: pink salmon; panasqueiraite: pinkish orange.
Panasqueiraite crystals are not known, but there are always exfoliation planes {010}, also for thadeuite (Caries Curto, Jordi Fabre: The Panasqueira Mines. The Mineralogical Record, January-February 2014, volume 45, number 1).
From specimens like these, this very rare species was identified: panasqueiraite. Identifying it in each sample is an almost impossible task. Panasqueiraite is a monoclinic calcium-magnesium phosphate, it would be an hydroxylated analog of isokite. In Panasqueira, its type locality, it is found as massive fine-grained aggregates together with other phosphates (fluorapatite, thadeuite, wolfeite, triplite, althausite and vivianite), with topaz, quartz and sulfides (arsenopyrite, pyrrhotite, chalcopyrite and sphalerite) in veins hydrothermal. The panasqueiraíta closely resembles the thadeuíta and the wolfeíta, but with the naked eye the three species can be distinguished by their slightly different colors: thadeuite: yellow-orange; wolfeite: pink salmon; panasqueiraite: pinkish orange.
Panasqueiraite crystals are not known, but there are always exfoliation planes {010}, also for thadeuite (Caries Curto, Jordi Fabre: The Panasqueira Mines. The Mineralogical Record, January-February 2014, volume 45, number 1).
Very sharp hexagonal fluorapatite crystal, with visible colour zoning, more intense in the core area and clearer in edges. Bright and defined, with another doubly terminated smaller crystal on one of the pinacoidal faces. It is accompanied by muscovite.
A first line arsenopyrite specimen from Panasqueira. It is a large group of prismatic lanceolate crystals of brilliant arsenopyrite, very defined, interpenetrated, with striated faces, ultimately: pure aesthetics. And to give it a touch of excellence we have a group of fluorapatite crystals, brilliant, transparent and with an uniform green tone. A more than worthy representative from this classic Portuguese mine.
This floater specimen shows a curious and aesthetic skeletal growth of arsenopyrite crystals. Oquerous, extremely brilliant, with flattened and striated forms. An exceptional piece for this Portuguese mine that never ceases to amaze us for its top quality specimens. A very different specimen from Panasqueira.
Group of hyaline quartz crystals, well developed and defined, with some curious crystals of fluorapatite, with a marked geometrical color zoning and inclusions. Theya re accompanied by brilliant pyrite crystals on muscovite and siderite.
Excellent combo formed by a group of ferberite crystals with parallel growths, with an intense black color and good brightness, peppered by lenticular siderite crystals. They are supported by a hyaline quartz crystal partially covered by muscovite. Note that quartz has a small dent on one of the faces of the terminal rhombohedra, without affecting the aesthetics of the sample. Arsenopyrite has grown on the ferberite. A specimen with a superb aesthetics, from a classic locality like Panasqueira.
Group of very sharp fluorapatite crystals showing defined prism faces and hexagonal dipyramids. Good transparence, color between green to greyish, depending on light. Very aesthetically disposed on a matrix of muscovite hexagonal rosettes, with white dolomite. Also with some cyclic twinned marcasite crystals, very brilliant and defined. Take a look under magnication lens. An excellent specimen from this Portuguese classic mine.