Trade Priority Support
Use the images (captured by our production team in Brazil) to see the visual differences between our two grades.
We don't sell "low quality." Whether you buy C1 (Premium) or C2 (Standard), the slate is structurally identical.
The grade refers only to the visual selection and aesthetic consistency.
Showcases the raw beauty of natural slate, featuring broader tonal shifts and unique markings for a timeless, organic look
Meticulously hand-selected to guarantee uniform colour, tone, and pattern across every piece.
The Authentic Hearth: Natural Riven Slate Our Natural Riven hearths are the perfect choice for those who appreciate the raw beauty of natural stone. With a textured, hand-split surface and a deep, tonal palette, these hearths offer a classic look that complements any interior. Heat-resistant, durable, and finished to the highest standard, they provide a lifetime of character for your fireplace.
Our standard grade celebrates the authentic diversity of the material. Because these slabs are not filtered for uniformity, you can expect a wider spectrum of colour, texture, and pattern. It is the perfect choice for those who appreciate a unique, organic look.
Our premium grade is meticulously hand-selected to guarantee uniform colour, tone and pattern across every slab.
To learn more about the differences between the two grades, please click here
Free delivery applies to full crates in England & Wales.
For other areas, please contact us for a quote
All prices are inclusive of VAT
Our Brazilian Riven Slate is known for its exceptionally "low-cleft" surface. Unlike Indian or Chinese slates, which can have aggressive ridges, our Brazilian slabs offer a flatter, more uniform split. This makes it ideal for fireplace hearths where a level surface is required for stoves to sit securely without excessive shimming.
Grading is based entirely on the natural surface split. Premium Grade slabs are selected for their near-flat surface and minimal riven texture. Standard Grade slabs exhibit more of the stone's organic character and traditional "steps." Both grades share the same structural integrity; the distinction is purely aesthetic to suit the design requirements of your project.
Yes. To save time on-site, our riven hearths are calibrated (machined) on the underside to a consistent thickness (typically 20mm or 30mm). This ensures that while the top remains natural and riven, the base is flat, allowing for a faster, more predictable bedding process with standard thin-set or floor adhesives.
Because Brazilian slate is a metamorphic rock with very fine grains, it is incredibly dense. While it can be cut precisely with a diamond blade, it does not "flake" or "delaminate" as easily as lower-quality slates. For a traditional look, we recommend using a pitching tool to dress the edges, which will reveal a clean, crisp snapped finish.
Brazilian slate has an extremely low water absorption rate (typically <0.5%). For fireplace applications, it is naturally resistant to heat and sparks. However, for trade handovers, we recommend applying a breathable impregnating sealer. This protects the riven ridges from soot and ash penetration while maintaining the stone's natural matte appearance.
To view our comprehensive FAQ section, click here
GRADING
The surface feels like leather after brushing. Sometimes called "antique" or "aged".
The brushing process "ages" the surface to make it feel "soft"
All sides are dressed - sides honed and top edge chamfered.
With sealant applied - the leather surface is more apparent.
The Brushed / Antique Leather Slate Collection: Discover a surface designed for the senses. Our Brushed Leather Slate collection features a signature "aged" texture that pairs antique warmth with a clean, contemporary edge. Each slab is hand-selected for its unique tonal character and finished with precision-chamfered edges for a seamless, high-end look. Perfect for those seeking an organic, matte finish that feels as incredible as it looks.
Free delivery applies to full crates in England & Wales.
For other areas, please get in touch with us for a quote
All prices are inclusive of VAT
Is brushed slate graded?
To get the best results from the brushing process, we use only standard-grade natural riven slabs. The Science: Brushing requires the natural texture and "character" found in the standard grade slabs. A Premium slab is often too uniform, resulting in a flat, dull finish when brushed. By using Standard Grade, you get a deeper, richer texture that looks superior. For a more detailed and science-backed explanation, please take a look at this blog
Collage
Sealing amplifies the cloud like appearance of the honed surface
All sides honed and chamfered as standard
Close up of surface
The Honed Slate Collection: Sleek, Smooth, and Sophisticated
Elevate your fireplace with the understated luxury of Brazilian Honed Slate. While the surface is precision-honed to a silky, flat finish, the stone retains its organic soul through subtle, cloud-like markings and soft tonal shifts. These natural "clouds" give the deep graphite surface a sense of movement and depth. It is the ideal choice for minimalist interiors or modern stove installations where you want clean lines paired with the unmistakable character of natural stone.
Free delivery applies to full crates in England & Wales.
For other areas, please contact us for a quote
All prices are inclusive of VAT
Precision Machining: Our honed slate is calibrated to a standard thickness of 20mm
Tolerances: We maintain a strict +/- 2mm tolerance to ensure level bedding and flush joints on-site.
Understanding Grade and Surface Character?
Process-Driven Aesthetics: Unlike our natural riven collection, where "Standard" and "Premium" grades are determined by the initial surface split, the final appearance of honed slate is only revealed during the machining process.
The "Honed Reveal": A slab that appears uniform or "plain" in its riven state can often exhibit significant cloud-like markings and tonal depth once the top layer is honed away.
Selection Criteria: Because the aesthetic character remains hidden until the stone is processed, we select our honed stock based on structural density and mineral composition rather than pre-honed surface appearance.
Project Planning: We advise trade professionals to view honed slate as a "living" natural material. The beauty of the finish lies in this unpredictability, ensuring that every hearth is a one-of-a-kind installation.
Thermal Rating: Naturally Grade A fire-rated and heat-resistant—ideal for solid fuel and gas hearths.
Density: Low porosity makes it naturally resistant to water; we recommend an impregnating sealer for oil and carbon protection.
Safety: The honed finish typically sits at an R9/R10 rating.
Application: Fireplace hearth, chamber and surround
Organic Character: The honing process reveals the stone’s internal grain, exposing unique, cloud-like markings that give each piece a distinct aesthetic.
Unique Aesthetic: Unlike standard riven slate, the honed finish ensures that no two slabs are identical. This natural variation is a hallmark of premium Brazilian stone and should be factored into the design intent when presenting to end clients.
Client Expectation Management: We recommend briefing clients on these tonal shifts before installation to ensure appreciation of the stone's natural diversity.
Visual Verification: For bespoke or single-slab orders, we can provide "pre-dispatch" photography upon request to confirm character. We don't offer visual verification for full-crate bulk orders due to logistical constraints.
A more rugged, riven texture. Almost jet black when sealed.
Our Black Limestone features a premium "orange-skin" texture
The texture is more visible and enhance when sealed
Elevate your fireplace with the grounding presence of Natural Black Limestone. While the surface features a sophisticated "orange-skin" stippled texture, the stone retains its organic soul through a dense charcoal grain and a tactile, matte finish. This unique stippling gives the deep obsidian surface a refined architectural weight while cleverly masking ash and surface smudges. It is the ideal choice for high-traffic hearths or traditional stove installations where you want a dramatic focal point paired with a durable, low-maintenance character.
Free delivery applies to full crates in England & Wales.
For other areas, please contact us for a quote.
All prices are inclusive of VAT.
What does the "orange-skin" texture actually feel like? Unlike honed slate, which is silky-smooth, our Black Limestone has a finely stippled, tactile surface similar to the rind of an orange. This "stippling" provides a sophisticated matte finish that is naturally slip-resistant and feels solid and architectural underfoot.
How does this texture help with maintenance? The "orange-skin" texture is incredibly practical for wood-burning stoves. While perfectly smooth surfaces show every speck of grey ash and fingerprint, the textured surface of limestone cleverly masks soot, dust, and light surface smudges, keeping your hearth looking cleaner for longer between wipes.
Is Black Limestone a "true black" colour? In its natural state, it is a deep charcoal or graphite grey. However, because of the textured surface, it takes stone enhancers and slate oils exceptionally well. When sealed, the stone transforms into a rich, dramatic obsidian black with a beautiful matte lustre.
Will it show scratches from logs or fireplace tools? All natural stone can scratch if mistreated, but Black Limestone is exceptionally dense and forgiving. The stippled texture helps to camouflage micro-scratches and general wear-and-tear much more effectively than a polished or flat-honed surface, making it ideal for high-use fireplaces.
Does it require a specific type of sealer? To maintain the bold, dark look described in our collection, we recommend using a high-quality slate dressing oil or colour intensifier. This seals the "orange-skin" pores, protecting the stone from stains while locking in that deep, timeless black aesthetic.
Overall grey with occasional tone and colour variation
Grey Limestone is significantly harder than Black Limestone, meaning it is only available with a sawn edge profile.
(sealed in picture, including edges)
Features the same "orange-skin" feel but with more natural variation; some areas will be more heavily textured than others.
(Sealed in picture)
Colour Shift: In its natural state, the stone has a uniform grey tone. Once sealed, the colour deepens significantly, revealing a warmer, brownish hue.
The "Homogenous" Look: Sealing both the surface and the sawn edges creates a consistent, high-end finish where the face and edges blend perfectly.
The "Contrast" Look: Leaving the edges unsealed creates a sharp visual contrast, where the exposed edge remains lighter than the darkened surface.
Trade Tip: For the best result, we recommend sealing all visible sides to ensure colour continuity across the entire hearth.
Elevate your fireplace with the rugged, architectural appeal of Natural Grey Limestone. While it shares the signature "orange-skin" stippled texture of our black variety, this stone is significantly harder, offering superior durability for heavy-duty installations. In its raw form, it displays a uniform, cool grey tone, but when sealed, it transforms, deepening in colour to reveal a sophisticated, warmer brownish hue. It is the ideal choice for those who want a clean, sawn-edge profile paired with the authentic, varied character of high-density natural stone.
Free delivery applies to full crates in England & Wales.
For other areas, please get in touch with us for a quote.
All prices are inclusive of VAT.
How does Grey Limestone differ from Black Limestone? Grey Limestone is a significantly denser and harder stone. While it shares a similar "orange-skin" texture, it is more rugged and specifically suited for heavy-duty fireplace installations. Due to its hardness, it is strictly finished with clean, sawn edges rather than hand-dressed profiles.
What does the "orange-skin" texture look like on the Grey variety? It features a tactile, stippled surface that provides excellent slip resistance. Unlike the Black Limestone, the texture on the Grey variety is more organic; you will see natural variations where some areas are slightly more textured than others, giving the hearth a more authentic, stone-earth feel.
Does the colour change when the stone is sealed? Yes, significantly. In its natural form, it has a uniform, cool grey tone. When a sealer or colour intensifier is applied, the stone deepens into a much darker graphite with a subtle, sophisticated brownish hue, adding warmth to the overall look.
Why is it important to seal the sawn edges as well as the surface? Because the edges are sawn, they expose the "raw" interior of the stone, which is lighter in colour. Sealing the edges alongside the surface ensures a "homogenous" look, blending the face and the profile into one consistent colour. Leaving the edges unsealed will result in a lighter, contrasting frame around the hearth.
How does this stone handle the demands of a busy fireplace? Grey Limestone is our most resilient limestone option. The combination of its extreme density and the stippled texture makes it highly resistant to scratches and impacts. The varied surface is also excellent at masking light ash and dust, making it a very low-maintenance trade favourite.
Check out this video to undertand the difference between natural riven, brushed and honed slate
The flatness test - for natural riven slate
From Brazilian Quarries to European Sites.
Wholesale container-direct shipping available across Europe. Quality-controlled at the source. Distributed by Bluesky Stone under our RioSlate Brand
Direct Delivery. No Middlemen
Carefully devanned by our Essex team and shipped as full crates directly to our HETAS customers. Efficiency in every mile, value in every crate.