- Home About RM Minerals
- Virtual Photo Museum Blog RM Contact
- Microscopy and instruments How to Buy Disclaimer
Copyright 2010-2025
www.rosellminerals.com
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.
A very good-sized specimen of schorl, with multiple prism faces and rhombohedral terminal faces. The brilliance is excellent and the black colour is very intense. A great specimen from this classic African locality.
Excellent specimen formed by numerous idiomorphic wulfenite crystals, richly faceted, brilliant, between transparent to translucent and with an intense orange color. They are accompanied by curious elongated tabular barite crystals. A really fine speciemen from Joan Viñals and purchased by E. Nicolau.
A large group of snowy laumontite crystals that have grown to cover the walls of an Alpine fissure. A rare specimen from this Swiss region.
Sample formed by several crystals of hercynite, var. picotite, a Mg, Cr rich member of spinel group: (Fe,Mg)(Al,Cr)₂O₄. Collected by Hal Miller in the 1960s, via Dave Shannon. Similar samples discussed in mindat.
A specimen of massive maroon coloured althausite, partly altered to apatite. Althausite may alter to apatite along the cleavage planes. This is especially typical for the althausite found at the type locality and Overntjern locality. This rare magnesium phosphate was first described from serpentine-magnesite deposits in Norway. Specimen acquired from David Shannon and from the Knut Larson collection.
Very good-sized specimen of rhombohedral dolomite crystals, very well defined and bright. Transparent to translucent, with greyish tones. Interpenetrated crystals. With an interesting and rare label from the former Sabadell mineral dealer "Blenda".
Berthierite is a rare iron antimony sulfosalt and not often found in good crystallized specimens. This piece is from the classic locality, the Baia Sprie Mine (Felsőbánya Mine) in Romania featuring dozens of acicular, silvery-grey needles of berthierite in nearly parallel growth, free of matrix. This rich specimen is beautifully accented with a variable iridescent tarnish, giving the piece much color and character. A wonderful example of this rare and classic material from a locality that was mined continuously from the 14th Century until 2006. From the collection of Julio Martínez (València).
Very defined barite crystal, with shapes of different orthorhombic prisms truncated by pinacoidal faces. The transparence is excellent. From this classic Moroccan mine for baryte crystals.
Rhombohedral dolomite crystal from this classic Navarra locality. It is disposed very aerial on a dolomite matrix. Three of the faces of the rhombohedron are dotted with small globules of goethite. A very aesthetic miniature.
In this specimen we could observe numerous aggregates of hexagonal gmelinite-Ca crystals, colorless, shiny and with parallel growths. They are accompanied by chabasita-Ca that gives this orange color to the specimen. Very difficult to find specimens of this quality and locality.
This specimen is interesting both for the species and for the locality. These are aggregates of pseudomalachite crystals that have grown in a fissure in the matrix formed mostly by quartz, in a small outcrop located on the slope of the "Cerro Viejo", near the Maidevera reservoir.
Very rich specimen formed by several cubic fluorite crystals, with polysynthetic growths on the faces and accompanied by microcrystalline quartz. Transparent to translucent. The violet to purple color is very intense and zoned. Some edges have small chips, but it is an old sample, from the mid-80s, from the collection of Julio Martínez (València).
Aggregates of tabular siderite crystals, with greenish tones, which are disposed on a matrix with small crystals of quartz, galena and baryte. The sample comes from this classic Almeria mine where it is not easy to find specimens of siderite with this quality. From the Aleydis Soliveres collection.
A good-sized specimen from this Extremadura mine formed by numerous bright andradite crystals, with defined faces, and accompanied by magnetite and an orthoclase crystal. From the Soliveres collection.
Specimen formed by a druse of quartz microcrystals on which several groups of cubic fluorite crystals have grown. They have faces that are asymmetrically beveled by the dodecahedron. Its transparency allows us to see a curious geometric zoning of color. The specimen comes from the J. Vilalta collection and the A. Soliveres collection. From a mine from which it is difficult to find pieces.
A very good sized piece of arsenatian vanadinite. Numerous crystals of very good size, interpenetrated, with good luster. A Moroccan classic not easy to find with this size, from the Cendón collection (Cerdanyola del Vallès).
Fehrite is a recent new species found in Almeria (Spain). Some years ago (2012) we identified this species in the Les Ferreres mine (Camprodon) but unfortunatelly we didn't have enough sample to finish detrmination and structural studies. Recently we found some more samples and the characterization was carried out based on the results obtained from the application of various analytical techniques: SEM-EDS, Raman and X-ray diffraction. Les Ferreres mine is the second locality worldwide for the species. We will send all reports to the buyer.
In this Catalan mine, fehrite appears as elongated elongated tabular to fibrous crystals, with a delicate bluish-green tone, and fibrous terminations. Usually, it is accompanied by devilline (blue) and brochantite (green). It is the magnesium analogue of ktenasite.
A very aesthetic specimen formed by a rich group of metatorbernite crystals. They present polysynthetic and echeloned growth of well-defined tetragonal crystals, with the characteristic green color. Under LW-UV we can observe the presence of a greenish-yellow fluorescence that indicates the presence of other species. SEM-EDS analysis have characterized this species as meta-autunite. We can say that the metatorbernite species is replacing the meta-autunite, as we can observe as a color gradation in some tabular crystals or in fresh fracture. We will send analysis to the buyer. This specimen come from late 90's finds in this classic French mine. Excol. A. Pouget, Excol Joan Rosell. The piece has a treatment that has kept it intact until today.
Both, meta-autunite and metatorbernite, are dehydrated phases of the autunite and torbernite. The loss of water molecules, those are present in the crystal structure of these species, is a common fact when the specimen is extracted from the mine.
Entraigas (Antraigas), Rodés, Avairon, Occitània, Entraigas, Rodés, Avairon, Occitània, França
Sylvite crystalline aggregate, colorless, transparent and shiny. Specimens of such pure sylvite are not easy to find. This comes from the potassium salt works of the Catalonia basin. Analyzed samples.
Sylvite crystalline aggregate, colorless, transparent and shiny. Specimens of such pure sylvite are not easy to find. This comes from the potassium salt works of the Catalonia basin. Analyzed samples.
Group of analcime crystals, with exceptional size, defined and faceted, with slightly curved edges. With small matrix of volcanic rock. These pieces are very old and difficult to find today. The piece is accompanied by a Marçal Lloria label, by Lloid.
Sheet of palygorskite, fibrous, laminated, delicate and at the same time resistant, silky and soft, like no other mineral species. It comes from the Magaña area, in Soria, and was acquired by Emili Nicolau from Joan Viñals in 1999. A Spanish curiosity.