Riven Black Slate Hearth – Bespoke Cut to Size & All Shapes
Riven Black Slate Hearth – Bespoke Cut to Size & All Shapes - 20mm - Lowest Cost / Up to - 90cm x 60cm - (XS) is backordered and will ship as soon as it is back in stock.
Cut to size Brazilian Riven Black Slate Hearths
Our black slate fireplace hearths are made to order from the highest-grade slate. Not only is this a premium natural material, but each hearth is also cut to your exact dimensions by our in-house team using high-tech CAD-guided saws, ensuring an accurate fit and a smooth, hassle-free installation in your home.
Often referred to as Black / Blue Slate, The naturally riven texture creates a traditional look that complements both modern and period homes. Naturally durable, heat-resistant and low-maintenance, Brazilian slate is an excellent choice for wood-burning stoves, open fires and fireplace hearths of all styles.
For a detailed breakdown of performance, tolerances and natural characteristics, please refer to the Specification tab where all key technical information is listed.
Easy Ordering Process
- ✓ Select Your Base Size: Choose the base size closest to your required dimensions from the dropdown menu.
- ✓ Choose Edge Details: Select your preferred edge finish — square, bevelled, eased or bull-nosed.
- ✓ Upload Your Drawing: Attach your drawing and include your cut-to-size measurements — we’ll take care of the rest.
Key Features
- ✓ Made to measure, cut to your exact size and shape
- ✓ Precision cut using advanced CAD machinery
- ✓ Choice of edge details to suit your design
- ✓ Fast 5-day delivery option — choose your delivery date at checkout
- ✓ No hidden costs or unexpected delays
- ✓ Ideal for quick installation and professional-looking results
| Product Specifications | |
|---|---|
| General | |
| Product Name | Brazilian Black Slate – Riven Hearth Grade |
| Material Type | Natural slate (metamorphic rock) |
| Category | Fire hearth slab / fireplace stone |
| Country of Origin | Brazil |
| Thickness Options | 20 mm, 30 mm, 50 mm |
| Colour Description | Deep blue-black base tone with charcoal variation and occasional mid-grey shading |
| Surface Finish | Riven natural split surface ranging from smoother areas to more rugged, pronounced markings |
| Natural Variation | Medium–high variation in texture, tone and surface markings typical of riven slate |
| Edge Finishing Notes | All edges are precision machine-cut and then hand-sanded if needed. Due to the natural structure of slate sanding marks, slight tonal variations along the edges and occasional tiny micro-chips may be visible. |
| Weight | Approx. 70–140 kg per m² depending on thickness |
| Density | Approx. 2,800–2,900 kg per m³ |
| Technical Characteristics | |
| Heat Absorption / Retention | Good thermal mass, absorbing heat efficiently and dispersing it evenly |
| Maximum Temperature Resistance | Safe up to approx. 450–500 °C before thermal shock risk. Must not contact open flame. |
| Compressive Strength | Approx. 100–150 MPa |
| Flexural Strength | Approx. 15–25 MPa |
| Porosity | Low–medium |
| Water Absorption | Approx. 0.3–1.0% |
| Thermal Conductivity | Approx. 2.0–2.5 W/mK |
| Chemical Sensitivity | Resistant to weak acids, but strong acids may cause surface bleaching |
| Stain Resistance | Moderate, greatly improved with sealing |
| Salt Sensitivity | Very low Brazilian slate is naturally stable and salt-resistant |
| Natural Characteristics of Brazilian Slate | |
| General Nature of the Stone | Brazilian riven slate forms naturally along cleft layers, resulting in a varied surface with both smoother and more deeply textured areas. Variations in tone, riven height and shading are normal and part of the stone’s authentic appearance. |
| Colour Profile – “Black Slate” | Although marketed as “Black Slate,” the true colour is a blue-black rather than a deep pure black. Blue, graphite and charcoal tones occur naturally within the stone. This is considered the darkest natural slate available, but customers should expect tonal movement rather than a uniform flat black. |
| Colour Patches & Mineral Movement | Natural mineral variations produce patches, cloudy areas or soft streaks across the surface. These features are inherent to genuine slate and contribute to each hearth’s individual character. |
| Riven Surface Texture | The riven texture is created during natural splitting. Some areas are gently undulating, while others show more pronounced ridges or cleft lines. No two pieces are identical — this variation is expected and valued for its rustic appearance. |
| Pyrite / Fools Gold | Pyrite can appear as small metallic gold or bronze flecks. Although less common than in limestone, it does occur naturally in slate and may appear on cut edges where internal minerals are exposed. This is not considered a fault. |
| Production Enhancements | We may use epoxy fillers, edge refinements, localised smoothing or colour-enhancing treatments to improve the final appearance. These professional finishing methods are industry standard and not considered defects. |
| Application & Packaging | |
| Suitable For | Fire hearths, stove bases, fireplace chambers, inglenooks and interior stone features. |
| Application | Internal use |
| Sealing | Sealing is recommended to reduce marking, enrich colour and improve stain resistance. |
| Installation Notes | Install on a stable, level substrate. Do not allow direct contact with flame. Use adhesives and sealers designed for natural stone. |
| Packaging | Supplied on reinforced wooden pallets or crates with protective packaging. |
| Availability | Cut-to-size hearths available in 20, 30 and 50 mm thicknesses subject to stock. |
At Primethorpe Paving, we strive to provide clear and straightforward delivery options to make your shopping experience seamless and transparent.
Below is a detailed breakdown of our delivery services.
Free Delivery*
Eligibility: Available on orders of £750 or more — this can include a single item or a combination of any products on our website.
Timeframe: 3–5 business days (exact delivery date provided at checkout)
Details: Enjoy complimentary delivery with no hidden fees on all eligible orders of £750 or more.
Exclusion Postcodes: IV40–49, IV51–54, KW15–17, HS, PA20, ZE, PA21–38, PA41–49, PA60–78, KA27–28, PH42–44, PO30–41, IM, JE, GY, BT — These postcodes will be charged at a higher delivery cost, provided upon enquiry.
Standard Delivery (£65)
Cost: £65
Timeframe: 3–5 business days
Details: Available for all orders under £750. Reliable delivery within the stated timeframe.
Exclusion Postcodes: IV40–49, IV51–54, KW15–17, HS, PA20, ZE, PA21–38, PA41–49, PA60–78, KA27–28, PH42–44, PO30–41, IM, JE, GY, BT — These postcodes will be charged at a higher delivery cost, provided upon enquiry.
Express Delivery (Additional £30)
Cost: +£30 on top of Standard Delivery
Timeframe: 1–2 business days
Details: Ideal for urgent orders. Orders placed before 12 PM are processed and shipped the same day.
Note: For orders over £750, you can upgrade to Express Delivery for an additional £30.
Smaller Items Delivery (£10)
Items: Jointing compound, cement, sealer, slurry, etc.
Cost: £10 per item
Additional Cost: £10 per additional item (up to 6 items). After 6 items, a flat rate of £60 applies.
Recess Covers Delivery (£20)
Cost: £20 per item
Additional Cost: £20 per additional item (up to 3 items). After 3 items, a flat rate of £60 applies.
Installation Essentials with Paving Orders (Free)
Cost: Free
Details: When smaller items or installation essentials (e.g., jointing compound, recess covers) are ordered alongside paving, cobble, walling, coping, or hearth products — delivery for these items is free.
Samples Delivery (Free)
Cost: Free
Details: All sample orders qualify for free delivery.
Bespoke Made-to-Measure Items Details:
Bespoke or made-to-measure items may take longer to deliver due to their custom nature. However, you will always receive an exact delivery date at checkout, so you’ll know precisely when to expect your order.
Cut to size Brazilian Riven Black Slate Hearths
Our black slate fireplace hearths are made to order from the highest-grade slate. Not only is this a premium natural material, but each hearth is also cut to your exact dimensions by our in-house team using high-tech CAD-guided saws, ensuring an accurate fit and a smooth, hassle-free installation in your home.
Often referred to as Black / Blue Slate, The naturally riven texture creates a traditional look that complements both modern and period homes. Naturally durable, heat-resistant and low-maintenance, Brazilian slate is an excellent choice for wood-burning stoves, open fires and fireplace hearths of all styles.
For a detailed breakdown of performance, tolerances and natural characteristics, please refer to the Specification tab where all key technical information is listed.
Easy Ordering Process
- ✓ Select Your Base Size: Choose the base size closest to your required dimensions from the dropdown menu.
- ✓ Choose Edge Details: Select your preferred edge finish — square, bevelled, eased or bull-nosed.
- ✓ Upload Your Drawing: Attach your drawing and include your cut-to-size measurements — we’ll take care of the rest.
Key Features
- ✓ Made to measure, cut to your exact size and shape
- ✓ Precision cut using advanced CAD machinery
- ✓ Choice of edge details to suit your design
- ✓ Fast 5-day delivery option — choose your delivery date at checkout
- ✓ No hidden costs or unexpected delays
- ✓ Ideal for quick installation and professional-looking results
| Product Specifications | |
|---|---|
| General | |
| Product Name | Brazilian Black Slate – Riven Hearth Grade |
| Material Type | Natural slate (metamorphic rock) |
| Category | Fire hearth slab / fireplace stone |
| Country of Origin | Brazil |
| Thickness Options | 20 mm, 30 mm, 50 mm |
| Colour Description | Deep blue-black base tone with charcoal variation and occasional mid-grey shading |
| Surface Finish | Riven natural split surface ranging from smoother areas to more rugged, pronounced markings |
| Natural Variation | Medium–high variation in texture, tone and surface markings typical of riven slate |
| Edge Finishing Notes | All edges are precision machine-cut and then hand-sanded if needed. Due to the natural structure of slate sanding marks, slight tonal variations along the edges and occasional tiny micro-chips may be visible. |
| Weight | Approx. 70–140 kg per m² depending on thickness |
| Density | Approx. 2,800–2,900 kg per m³ |
| Technical Characteristics | |
| Heat Absorption / Retention | Good thermal mass, absorbing heat efficiently and dispersing it evenly |
| Maximum Temperature Resistance | Safe up to approx. 450–500 °C before thermal shock risk. Must not contact open flame. |
| Compressive Strength | Approx. 100–150 MPa |
| Flexural Strength | Approx. 15–25 MPa |
| Porosity | Low–medium |
| Water Absorption | Approx. 0.3–1.0% |
| Thermal Conductivity | Approx. 2.0–2.5 W/mK |
| Chemical Sensitivity | Resistant to weak acids, but strong acids may cause surface bleaching |
| Stain Resistance | Moderate, greatly improved with sealing |
| Salt Sensitivity | Very low Brazilian slate is naturally stable and salt-resistant |
| Natural Characteristics of Brazilian Slate | |
| General Nature of the Stone | Brazilian riven slate forms naturally along cleft layers, resulting in a varied surface with both smoother and more deeply textured areas. Variations in tone, riven height and shading are normal and part of the stone’s authentic appearance. |
| Colour Profile – “Black Slate” | Although marketed as “Black Slate,” the true colour is a blue-black rather than a deep pure black. Blue, graphite and charcoal tones occur naturally within the stone. This is considered the darkest natural slate available, but customers should expect tonal movement rather than a uniform flat black. |
| Colour Patches & Mineral Movement | Natural mineral variations produce patches, cloudy areas or soft streaks across the surface. These features are inherent to genuine slate and contribute to each hearth’s individual character. |
| Riven Surface Texture | The riven texture is created during natural splitting. Some areas are gently undulating, while others show more pronounced ridges or cleft lines. No two pieces are identical — this variation is expected and valued for its rustic appearance. |
| Pyrite / Fools Gold | Pyrite can appear as small metallic gold or bronze flecks. Although less common than in limestone, it does occur naturally in slate and may appear on cut edges where internal minerals are exposed. This is not considered a fault. |
| Production Enhancements | We may use epoxy fillers, edge refinements, localised smoothing or colour-enhancing treatments to improve the final appearance. These professional finishing methods are industry standard and not considered defects. |
| Application & Packaging | |
| Suitable For | Fire hearths, stove bases, fireplace chambers, inglenooks and interior stone features. |
| Application | Internal use |
| Sealing | Sealing is recommended to reduce marking, enrich colour and improve stain resistance. |
| Installation Notes | Install on a stable, level substrate. Do not allow direct contact with flame. Use adhesives and sealers designed for natural stone. |
| Packaging | Supplied on reinforced wooden pallets or crates with protective packaging. |
| Availability | Cut-to-size hearths available in 20, 30 and 50 mm thicknesses subject to stock. |
At Primethorpe Paving, we strive to provide clear and straightforward delivery options to make your shopping experience seamless and transparent.
Below is a detailed breakdown of our delivery services.
Free Delivery*
Eligibility: Available on orders of £750 or more — this can include a single item or a combination of any products on our website.
Timeframe: 3–5 business days (exact delivery date provided at checkout)
Details: Enjoy complimentary delivery with no hidden fees on all eligible orders of £750 or more.
Exclusion Postcodes: IV40–49, IV51–54, KW15–17, HS, PA20, ZE, PA21–38, PA41–49, PA60–78, KA27–28, PH42–44, PO30–41, IM, JE, GY, BT — These postcodes will be charged at a higher delivery cost, provided upon enquiry.
Standard Delivery (£65)
Cost: £65
Timeframe: 3–5 business days
Details: Available for all orders under £750. Reliable delivery within the stated timeframe.
Exclusion Postcodes: IV40–49, IV51–54, KW15–17, HS, PA20, ZE, PA21–38, PA41–49, PA60–78, KA27–28, PH42–44, PO30–41, IM, JE, GY, BT — These postcodes will be charged at a higher delivery cost, provided upon enquiry.
Express Delivery (Additional £30)
Cost: +£30 on top of Standard Delivery
Timeframe: 1–2 business days
Details: Ideal for urgent orders. Orders placed before 12 PM are processed and shipped the same day.
Note: For orders over £750, you can upgrade to Express Delivery for an additional £30.
Smaller Items Delivery (£10)
Items: Jointing compound, cement, sealer, slurry, etc.
Cost: £10 per item
Additional Cost: £10 per additional item (up to 6 items). After 6 items, a flat rate of £60 applies.
Recess Covers Delivery (£20)
Cost: £20 per item
Additional Cost: £20 per additional item (up to 3 items). After 3 items, a flat rate of £60 applies.
Installation Essentials with Paving Orders (Free)
Cost: Free
Details: When smaller items or installation essentials (e.g., jointing compound, recess covers) are ordered alongside paving, cobble, walling, coping, or hearth products — delivery for these items is free.
Samples Delivery (Free)
Cost: Free
Details: All sample orders qualify for free delivery.
Bespoke Made-to-Measure Items Details:
Bespoke or made-to-measure items may take longer to deliver due to their custom nature. However, you will always receive an exact delivery date at checkout, so you’ll know precisely when to expect your order.
