Mustang Schiefer is a high-grade Brazilian clay slate (Bambui Graphite Slate) from Papagaios in Minas Gerais, with a dense, anthracite-black base colour and a fine graphitic shimmer. One of the most widely installed black slates on the German market for floor areas, wall claddings, roofing, exterior paving, stairs and prestigious interior and exterior architecture.
Slate
Brazil
Säurebeständig
2.750 kg/m³
Available as: Slabs, Skirting, Paving slabs, Tiles and flooring slabs
Other trade names: ARDOSIA PRETA, Black Slate, Cumbria Black, MONTAUK BLACK, MUSTANG, Malta Nightblue, Montank Black, Mustang Black Slate, Mustang Brazilian Slate, Mustang Slate, Nero Mustang Slate, PANTHER BLACK, Papagaios Black, RO-07-017
About Mustang Schiefer
Mustang Schiefer is one of the most popular black slate varieties on the German and Central European market — a Precambrian Brazilian clay slate with a graphitic component, quarried near Papagaios north of Belo Horizonte in the state of Minas Gerais. It is characterised by a dense, even anthracite-black to dark grey base colour with the fine, slightly metallic shimmer created by the graphite it contains. The appearance of the slab is calm and evenly figured throughout, with a restrained mottled texturing (“mottled” according to the DNSA description); unlike many Indian or Chinese slates, colour consistency across the slab surface is very high — a clear advantage for large projects with many individual slabs. On the international market the material also runs under the trade names MUSTANG, MONTAUK BLACK, PANTHER BLACK, ARDOSIA PRETA (Portuguese for “black slate”), Mustang Slate, Mustang Brazilian Slate, Nero Mustang Slate and Mustang Black Slate. At ROSSITTIS we carry Mustang Schiefer for floor areas, wall claddings, roofing, exterior paving, garden stepping slabs, pool surrounds, staircases, plinth details, kitchen worktops, bar counters, washstand tops and project-specific bespoke work.
Geologically, Mustang Schiefer is a Precambrian clay slate from the Bambui formation in Minas Gerais — geologically one of the oldest and most significant sedimentary sequences of the South American shield. DNSA documents the material under entry 5586 (INSK 57.9) with the main name BAMBUI GRAPHITE SLATE. Clay slates are formed by low-grade metamorphosis of ancient clay sediments under moderate pressure and temperature — the fine clay minerals are cemented into parallel layers that make the material cleavable into thin, flat slabs. The graphite content arises from the carbon component of the original organic sediments and gives the material its characteristic deep black colour and its restrained metallic shimmer. DNSA documents the stone as “frequently used in Germany” — Mustang Schiefer is one of the most widely installed black natural slates in the German-speaking region and has been the standard for high-quality flooring and exterior architecture projects for decades.
The technical values are exceptional for a slate: bulk density 2,750 kg/m³, compressive strength 272 MPa (one of the highest among all natural slates worldwide), flexural strength 38.6 MPa (extremely high), water absorption 0.48 percent. The compressive strength of 272 MPa lies well above the values of most European and Indian slates and on a level with high-quality granites — which makes Mustang Schiefer particularly suitable for heavily loaded floor areas, staircases and exterior paving. DNSA confirms acid resistance within the normal range of application, which makes the stone considerably easier to care for than many other slates. Frost resistance is assured in the Central European climate — Mustang Schiefer has been proven as an exterior and roofing slate in Germany for decades. Compared with classic Spanish roofing slate, Mustang is denser, more robust and has a considerably more even colour characteristic; compared with Indian black slates, the colour saturation is deeper and the appearance of the slab calmer.
At ROSSITTIS, Mustang Schiefer is available as a raw slab, as floor tiles (in standard and special sizes), as tread and riser, as a window sill, as skirting, as wall facing, as exterior paving stone, as a garden stepping slab, as roofing slate and as a project-specific cut; likewise as a kitchen worktop and washstand top. The surface finishes available in stock are listed in the »Finishes« block further down.
Our honest assessment: Mustang Schiefer is a first-class choice for projects looking for a high-grade black slate with full technical load capacity and a calm, even appearance. The combination of a dense anthracite-black base colour, exceptionally high compressive strength (272 MPa), acid resistance and frost resistance makes the material suitable without restriction for demanding interior and exterior applications. One important clarification: Mustang Schiefer (clay slate from Brazil) is not to be confused with Mustang Quartzite or White Mustang Quartzite — those are completely different materials from different deposits. Anyone looking for a warm, rustic slate should choose an Indian Multicolor or Copper Slate; for a demanding black slate with the highest robustness, Mustang is the reference.
In stock
Current availability from our warehouse.
457 slabs in stock · plus 183 blocks
Thicknesses: 1–6 cm · Finishes: Satin-honed, Riven, calibrated, Satin-honed, calibrated and more · Available as: Slabs, Skirting, Paving slabs, Tiles and flooring slabs
Guide values for the stone type, taken from manufacturer and test reports. Natural stone is a natural product — individual batches and slabs can differ. For critical applications, request slab-specific test data.
Mustang Schiefer is available in a range of finishes. The finish affects appearance, feel and the care it needs.
Satin-honed
The surface is brushed — softer minerals are selectively removed, creating a subtle depth with a matte appearance. A restrained finish that shows the layering typical of slate in an elegant matte quality. Easier to maintain than the polished variant and suited to everyday use.
Riven, calibrated
Like riven (a naturally split, rough matte surface), additionally with a calibrated reverse: the underside of the slab is ground level for an even thickness and simplified installation. Recommended for outdoor areas, paving and bonded façade applications that demand precise dimensional accuracy.
Satin-honed, calibrated
As for the satin finish (a brushed matt surface with subtle depth), but additionally with a calibrated reverse: the underside of the slab is ground flat for an even thickness and simplified installation. Recommended for floor areas, stair treads and bonded fixings that demand precise dimensional accuracy.
Honed C600, calibrated
As for honed C600 (a very fine honed finish with clear colour intensity and barely visible honing marks), but additionally with a calibrated reverse: the underside of the slab is ground flat for an even thickness. Recommended for high-quality floor areas and wall claddings that demand precise dimensional accuracy.
Bamboo
A special surface with a characteristic longitudinal-groove texture reminiscent of a bamboo look — the colour appears restrained, the appeal rustic and strong in design. A striking finish for wall claddings as an eye-catcher in designed interiors, less suitable for heavily used horizontal surfaces.
Riven
The surface corresponds to a natural splitting of the rock — the layered characteristic typical of slate comes fully into its own. A matt, rough appeal with high slip safety and an originally natural effect. Recommended for outdoor areas, wall claddings and heavily used paved surfaces.
Care & fabrication
As a high-grade Brazilian clay slate, Mustang Schiefer can be maintained over the long term and cleaned without difficulty. With a water absorption of 0.48 percent and the acid resistance confirmed by DNSA, the material is considerably easier to care for than many other slates. Immediately after laying we recommend an impregnation on a silane or polysiloxane basis — it emphasises the depth of the black base colour at the same time as protecting against water marks and strongly colouring substances such as red wine, coffee or oil. Ongoing cleaning is carried out with a pH-neutral natural stone cleaner and a soft microfibre cloth or mop; on riven surfaces, more deeply seated soiling can be removed with soft scrubbing brushes. You should avoid strongly alkaline intensive cleaners, abrasive steel wool and hard brushes. Outdoors, Mustang Schiefer is frost-resistant and has been proven as a German exterior building stone for decades — de-icing salt residue should be rinsed off with clear water in spring. We recommend refreshing the impregnation every three to five years, depending on the loading.
Frequently asked questions
What other designations does Mustang Schiefer carry?
On the market the material runs under numerous trade names: Mustang Schiefer (the main German designation), MUSTANG (the DNSA trade name), MONTAUK BLACK, PANTHER BLACK, Mustang Slate, Mustang Brazilian Slate, Nero Mustang Slate, Mustang Black Slate and ARDOSIA PRETA (Portuguese for “black slate”). The main DNSA name is BAMBUI GRAPHITE SLATE — after the Bambui formation the material comes from.
What technical values does Mustang Schiefer have?
From the DNSA entry (5586): bulk density 2,750 kg/m³, compressive strength 272 MPa (one of the highest among all natural slates), flexural strength 38.6 MPa, water absorption 0.48 percent. Acid resistance within the normal range of application, frost resistance confirmed by DNSA. The compressive strength is on a level with high-quality granites — exceptional for a slate.
Which finishes are available for Mustang Schiefer?
The surface finishes available in stock are listed in the »Finishes« block on this page.
Is Mustang Schiefer suitable for outdoor use?
Yes, very much so. Mustang Schiefer is frost-resistant according to DNSA and has been proven as a German exterior and roofing slate for decades. With a compressive strength of 272 MPa and a low water absorption of 0.48 percent, the material is suitable without restriction for paving, stairs, façades, pool surrounds and roofing. Rinse off de-icing salt residue with clear water in spring.
Is Mustang Schiefer suitable for kitchen worktops?
Yes. Unlike many other slates, Mustang is suited to everyday use for kitchen worktops thanks to its high compressive strength (272 MPa), its acid resistance and its low water absorption — including in the polished version. Wine, lemon juice or vinegar leave no etch marks. A silane-based impregnation additionally protects against strongly colouring substances such as red wine and oil.
Mustang Schiefer or Spanish roofing slate — what is the difference?
Spanish natural slates from Galicia are classic thinly cleavable roofing slates with finer layering and somewhat lower compressive strength, ideal for period-style roofing. Mustang Schiefer from Brazil is denser, considerably stronger in compression (272 MPa versus a typical 100–150 MPa for the Spanish ones) and has a more even colour signature — it is the choice for high-quality flooring and exterior architecture projects and also for demanding modern roofing where robustness over decades is required.
What distinguishes Mustang Schiefer from Mustang Quartzite?
Very important — the designations are confusingly similar, but these are two completely different materials: Mustang Schiefer (BAMBUI GRAPHITE SLATE) is a black clay slate from Minas Gerais; Mustang Quartzite is a light, multicoloured quartzite from a different Brazilian deposit. With “Mustang Schiefer”, ROSSITTIS consistently supplies the black slate material identified by DNSA.
What does Mustang Schiefer cost?
The price depends on the batch, thickness, surface finish and fabrication — with natural stone there is no serious flat rate per square metre. Business customers see prices once their B2B account is activated; private customers receive a complete quote through a fabricator near them.
Projects using Mustang Schiefer
Projects in which Mustang Schiefer has been used successfully.
