Migmatit

Listed in our range under Granite.

Rio Nero

Rio Nero is an expressive Brazilian migmatite of the granite trade family from the state of Rio Grande do Sul, with a dramatically flowing migmatitic band structure — alternating anthracite-black and creamy honey-coloured layers create an animated slab image like churned water or a geological storm surge. Internationally also listed as Preto Rio Nero and within the wider Rio Negro / Rio Preto family; used for expressive statement wall claddings, bookmatch compositions, bar counters, designer kitchen worktops and prestigious interior floor surfaces.

Rio Nero is petrographically a Brazilian migmatite from Rio Grande do Sul — a metamorphic hybrid rock type with a characteristic black, creamy honey-coloured band structure. Listed in international trade as a granite; at ROSSITTIS we classify Rio Nero in the granite family in the customary way, in line with the trade convention for Brazilian hard rock migmatites. Related trade synonyms are Preto Rio Nero and Rio Negro Granite.

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Available as: Slabs · 1 of 33 reserved

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About Rio Nero

Rio Nero shows an exceptionally expressive, dynamic slab character with a flowing migmatitic band structure. The composition alternates in horizontally running bands between deep black, anthracite-grey and warm creamy honey-coloured to bronze layers — the movement structure recalls churned water, frozen currents or geological storm bands that have solidified into stone. Between the layers there are subtle brown and copper-coloured mineralisations from iron oxide inclusions. The individual bands are not strictly linear but slightly wavy and irregular — some areas denser, with more pronounced black-cream contrasts, others with converging transitions in which the colours merge into one another. On a polished surface the stone develops an exceptional depth effect — the black bands appear almost mirror-like, while the light layers shimmer with a warm silkiness and the copper-coloured mineral sections stand out luminously. Every slab image is a unique piece — with Rio Nero it is particularly worthwhile to select from real slab images, because the band distribution varies strongly from block to block. The stone is outstandingly suited to bookmatch laying (mirror-image laying), because with two slabs mirrored side by side the flowing band structures produce dramatic, storm-like large-scale motifs.

Geologically, Rio Nero is a Precambrian migmatite from the Brazilian state of Rio Grande do Sul (in the south of Brazil) — the quarries lie in the São Marcos / Santa Maria region, with quarry designations such as Rosário and Colônia. The stone belongs to the wider family of black-and-cream Brazilian migmatites and hard rock banded stones, which in the trade are partly also traded as Preto Rio Nero, Rio Negro Granite (with a similar migmatitic appearance) or generally as “Brazilian Black & Gold” grades. Petrographically a migmatite — a metamorphic hybrid rock type in which light quartz- and feldspar-rich melt layers (leucosome) alternate with dark biotite- and amphibole-rich residual sections (melanosome). On the market, Preto Rio Nero and Rio Negro are listed as related aliases, which points to a shared trade family.

The typical technical properties of Brazilian migmatites are high compressive strength, low water absorption, a Mohs hardness of around 6.5–7 and full acid resistance thanks to their silicate character — wine, lemon juice, vinegar or sanitary cleaners leave no etch marks. For large-area external applications we recommend requesting a project-specific data sheet from the importer.

At ROSSITTIS we stock Rio Nero as an unsized slab in 20 mm and 30 mm thickness for expressive statement applications, in tiles for floor and wall applications, as a tread and riser for staircases, as a window sill, as a skirting and for project-specific cutting to size. For designer kitchen worktops, too, the stone can be used to expressive effect given its dramatic appearance. The finishes available from stock are listed in the »Finishes« block further down.

Compared with more uniform black granite classics such as Nero Assoluto Zimbabwe or Nero Africa, Rio Nero brings the dramatically livelier, more animated slab appearance. Set against black-and-cream migmatite classics such as Black Cosmic (with finer striping), Mascarello (with more brown-bordeaux tones) or Black & Gold (an Italian marble with golden vein traces), Rio Nero appears more expressive in its directional band structure and higher in contrast through its strong black-cream transitions. For architectural projects with a dramatic material effect — designer kitchens with a high-contrast black-cream accent, hotel lobbies with bookmatch wall surfaces, restaurant bar counters with a flowing band structure and prestigious statement interior surfaces — Rio Nero is a very exclusive and expressive choice in the upper premium segment of Brazilian migmatites.

In stock

Current availability from our warehouse.

33 slabs in stock — 32 available now, 1 reserved · plus 3 blocks

Thicknesses: 2 & 3 cm · Finishes: Polished, Satin-honed, lapatura®|caress|reptil · Available as: Slabs

Updated daily from our live stock.

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Finishes

Rio Nero is available in a range of finishes. The finish affects appearance, feel and the care it needs.

Polished

Polishing is the most classic finish in the hard stone segment — a mirror-smooth, high-gloss surface with the highest possible colour intensity and maximum depth effect in the mineral structure. As an acid-resistant silicate stone, polished granite is easy to care for and the first choice for kitchen worktops, wall claddings and prestigious exposed surfaces.

Satin-honed

The satin surface is created by brushing, which selectively removes softer minerals and gives the surface a slight depth. A matte appearance with subtle light reflection and a warm feel to the touch. Easy to maintain, insensitive to scratches and suited to everyday use — a popular alternative to a polish in modern kitchens and living spaces.

Care & fabrication

As a Brazilian migmatite, Rio Nero is a robust hard rock with low water absorption, full acid resistance and a Mohs hardness of around 6.5–7. Wine, lemon juice, vinegar, cola, sanitary cleaners or descalers leave no etch marks as they would on marble or limestone — the stone is considerably easier to care for and well suited to intensive everyday use.

For interior applications we recommend an impregnation on a silane or polysiloxane basis at initial installation. On the heterogeneous migmatite surface, impregnation is particularly important, because otherwise oil, grease and pigment stains can settle more visibly on the lighter creamy honey-coloured layers than on the black bands. On polished interior surfaces a renewal every 5–8 years is sufficient; on heavily used kitchen worktops, check every 2–3 years.

Daily care is carried out with a pH-neutral natural stone cleaner and a soft cloth or microfibre mop. Clear warm water is usually sufficient. Acidic cleaners are fundamentally unproblematic, but should nevertheless not be used, because they can attack the impregnation. The finishes available from stock are listed in the »Finishes« block further down.

For kitchen worktops Rio Nero is well suited: cut- and scratch-resistant, insensitive to heat (hot pots and pans can be set down directly for a short time, although prolonged heat exposure above 200 °C should still be avoided), acid-resistant and with good stain repellency. The expressive band structure conceals small traces of use remarkably well. For the Lapatura® Caress Reptil finish (leathered and structured, with a reptile-like microstructure) a particular care instruction applies: the structured surface can be harder to clean than smooth surfaces when heavily soiled — work with a soft brush and a pH-neutral cleaner, and occasionally work down into the deeper structural layers with a microfibre cloth after damp cleaning. The finishes available from stock are listed in the »Finishes« block further down.

For external applications we recommend a project-specific data sheet check of the frost resistance before ordering. If released for external use, a matt, structured finish is advisable for slip resistance. Polished external surfaces can show minimal losses of gloss after years in locations with heavy UV exposure. In areas with frequent salt contact we recommend an additional annual renewal of the impregnation.

Frequently asked questions

What is Rio Nero geologically?

Rio Nero is a Brazilian migmatite from the state of Rio Grande do Sul (the São Marcos / Santa Maria region) — a metamorphic hybrid rock type in which light quartz- and feldspar-rich melt layers (leucosome) alternate with dark biotite- and amphibole-rich residual sections (melanosome). In international trade the stone is listed in the granite family; at ROSSITTIS we classify Rio Nero as a granite in the customary way, in line with the widespread trade convention for Brazilian hard rock migmatites. On the market, Preto Rio Nero and Rio Negro are listed as related trade aliases.

Which synonyms exist for Rio Nero?

In international trade Rio Nero also runs under designations such as Preto Rio Nero, Rio Negro Granite, Rio Preto-related, and generally as a “Brazilian Black & Gold” grade. The designation “Rio Nero” (Italian for “black river”) refers to the flowing dark band structure.

What is Lapatura® Caress Reptil?

Lapatura® Caress Reptil is a special finish with a leathered, structured surface and a reptile-like microstructure. The surface combines the depth effect of the polished black-cream bands with a haptically deep, velvety structure — the migmatitic band image emerges sculpturally and becomes perceptible to the hand. A premium treatment for designer compositions with the highest material ambitions, very popular for expressive statement wall claddings and exclusive bar counters.

Is Rio Nero suitable for bookmatch laying?

Outstandingly suited. With bookmatch laying (mirror-image laying of two slabs), the flowing, directional black-cream bands produce symmetrical, storm-like large-scale motifs — squall-like mirror images or flowing symmetrical layerings with the characteristic black-cream composition. For prestigious wall claddings, bar counters and designer statement surfaces, bookmatch is a very fitting composition.

Is Rio Nero suitable for a kitchen worktop?

Yes, well suited. With a Mohs hardness of around 6.5–7, low water absorption and full acid resistance, Rio Nero is cut-, scratch- and heat-resistant and absorbs no wine, lemon or vinegar acids. The expressive band structure conceals small traces of use remarkably well and suits designer kitchens with a deliberately dramatic material composition. For a calm kitchen with less visual weight we recommend alternative grades such as Nero Assoluto Zimbabwe.

Which finishes are available for Rio Nero?

The finishes available from stock are listed in the »Finishes« block on this page.

Where does Rio Nero come from?

Rio Nero comes from Brazil — the quarries lie in the state of Rio Grande do Sul, in the São Marcos / Santa Maria region. Well-known quarry designations from the region are Rosário and Colônia. The region is among the Brazilian migmatite provinces that produce expressive hard rock grades for the world market.

How do I clean and care for Rio Nero?

As a Brazilian migmatite, Rio Nero is very easy to care for: daily care with a pH-neutral natural stone cleaner and a microfibre cloth is sufficient. We recommend an impregnation at initial installation; for interior applications a renewal interval of 5–8 years depending on use, and on heavily used kitchen worktops check every 2–3 years. With the Lapatura® Caress Reptil finish, cleaning with a soft brush and occasionally working down into the structural layers is advisable. Dry cleaning with a soft microfibre cloth after damp mopping is recommended.

What does Rio Nero 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.