Brazilian black riven slate hearth slab, calibrated flat with 90 degree machine-sawn edges, natural cleft surface

Brazilian Black Riven Slate Hearth

£95.00 inc. VAT

★★★★★ 4.84/5 · 694 reviews✓ In stock
Crack Guarantee ⓘ
Fit your hearth within 14 days of delivery. If a single hearth slab cracks in that time, we replace it free. Cut pieces included. Full crates, coping, paving and samples are not covered.
Free Photo Service ⓘ
Premium orders always include a photo of your exact slab before dispatch. Standard orders include it when a finishing service is added.
Guaranteed Level Surface ⓘ
Guaranteed flat riven texture — a standard credit card slides smoothly across the surface without catching.

Not the size you need?

We cut riven, honed or brushed slate to your exact size, up to three matching pieces from one slab. From £163.

Not sure which stone is right? Order a sample first ➔

Delivered kerbside on a pallet — please arrange help for the day.

Provide your installer's details and our team will get in touch with them directly.

On single hearth slabs
  • ✓ 14-day crack guarantee, single slabs Fit it within 14 days of delivery. If it cracks in that time, we replace it free. Cut pieces included. Full crates are not covered.
  • ✓ A credit card slides across without catching Every slab is tested, whichever grade you choose. Your stove sits flat and does not rock.
  • ✓ 28-day returns on stock sizes Unused, in its original packaging. You arrange and pay the return carriage — it is a palletised slab, so it is not cheap, and we would rather say that here. Cut-to-size pieces are made for you, so they can't come back — see Cut to Size.
  • ✓ Container-direct, from our own yard No middleman and no showroom markup. You buy from the yard that imports it, at yard prices.
Choices you only get here
  • + Three surfaces, not two Riven, honed and brushed — all from the same Brazilian quarry. Most suppliers stop at two.
  • + You pick the grade Raw natural character, or hand-sorted for even tone. Your call, not ours — and you make it before you pay, not on delivery.
  • + Sealed in our workshop, or not at all Deep Clean & Seal if you want it fitted-and-finished. Leave it off and oil it yourself — we don't mind which.
  • + A photo of your actual slab Included with Premium grade, or with any finishing service. Not a stock image — the piece with your name on it.

We cut rectangles, squares and the two-piece T-set. If your opening needs a circle, a teardrop or a one-piece T, we're not your supplier — and we'll say so rather than waste your time.

Key Specifications

  • Dimensions: 1200×900 · 900×600 · 900×900 · 1500×900 — 20mm & 30mm
  • Material: Brazilian Black Riven Slate
  • Primary use: Wood-burning stove hearths
  • Guarantee: 14-Day Crack Guarantee
  • Photo service: Free photo of your exact slab before dispatch
Overview

Container-direct Brazilian black riven slate hearths, supplied by Bluesky Stone Direct from Milton Keynes and Colchester. Four stock sizes, two thicknesses, two grades — all from the same quarry, all held in stock.

Rectangles, done properly, this week. We cut rectangles, squares and the two-piece T-set. If your opening needs a circle, a teardrop or a one-piece T, we are not your supplier — and we would rather say so here than waste your time.

Four stock sizes, 20mm or 30mm, with real weights
Size Thickness Weight
900 × 600 20mm 30 kg
900 × 900 20mm 45 kg
1200 × 900 20mm 61 kg
1500 × 900 20mm 76 kg
1200 × 900 30mm 91 kg
1500 × 900 30mm 113 kg

All slabs are calibrated to ±1mm with clean 90° machine-sawn edges. 30mm is made in 1200×900 and 1500×900 only. Every slab is a two-person lift and is delivered kerbside on a pallet.

20mm or 30mm is a look choice. 30mm has a thicker edge and a more substantial look, and is heavier to lift. Both thicknesses suit any hearth. As always, check with your installer in case there is a specific reason to choose differently.

Flat enough to pass the credit card test
  • 14-Day Crack Guarantee. Fit it within 14 days of delivery. If it cracks in that time, we replace it free. Cut pieces included. Full crates are not covered.
  • The credit card test. Every slab must let a standard credit card slide across the riven surface without catching on a ridge. A hearth that rocks under a stove is the fault nobody checks for.
  • Container-direct pricing. Brazilian slate bought by the container, not through a UK middleman.
  • Free pre-dispatch photo of your actual slab on every Premium order, and on any Standard order with a cutting or finishing service added.
  • Free collection from our Milton Keynes workshop (MK8 8DD), booked at checkout, usually ready the next working day.
Standard or Premium: same stone, chosen differently

Both grades are the same stone, the same thickness and the same test results. The difference is how the slab is chosen.

  • Standard Grade — the raw character of natural stone, with visible variation in texture, tone and pattern.
  • Premium Grade — hand-sorted for even tone, so the face reads as one consistent colour.

Neither grade changes the edge finish: both come with clean 90° machine-sawn edges.

Tested for stove heat, slip and frost
  • Slip resistance: PTV 62 dry / PTV 49 wet — low slip risk
  • Flexural strength: 19.6 MPa after 48 freeze-thaw cycles
  • Water absorption: under 0.50% — high frost resistance
  • Surface: subtle natural riven
  • Edge: clean 90° machine-sawn as standard
  • Colour: graphite grey to black in its raw state. Sealing takes it to a noticeably deeper, darker tone.
  • Suitability: designed for the weight and radiant heat of a wood-burning or multi-fuel stove. Not for direct flame contact.
Raw or sealed: arrives the way you want to fit it
  • Unsealed — included. Delivered in 3–5 working days.
  • Deep Clean & Seal — £75. Deep-cleaned to remove quarry dust, then two coats of Stovax Dressing Oil. This is what takes the stone from grey to black. Allow one extra working day for the oil to dry.

Need a size we don't stock? Cut to Size cuts up to three matching pieces from one slab, from £163 including the slab. Standard 14 days or Priority 7 days.

One delivery charge per order, or collect free
  • Collection from Milton Keynes (MK8 8DD) is booked at checkout, usually ready the next working day.
  • Collection from Colchester (CO6 2JX) is arranged by phone. Call 01908 46 46 56 to confirm availability and any handling fee.
  • Delivery to England and Wales is one charge per order, not per slab, shown beside the price above and confirmed at checkout.
  • Scotland, Northern Ireland and the Islands — costs vary by postcode, so we quote individually. Call 01908 46 46 56 or email sales@blueskystone.com.
  • Delivered kerbside by pallet via a nationwide carrier.
Fitting several? A full crate costs less per slab

Full crates carry a lower per-slab rate and ship free to England and Wales. Crate quantities vary by size — 30 slabs for 900×600, 15 for 900×900 and 1200×900, 12 for 1500×900, 10 for 30mm. See the full-crate page for crate pricing, or open a trade account.

30-day returns on stock sizes

30 days from delivery on stock sizes, unused and in the original packaging, with no restocking fee. You arrange and pay the return pallet, which costs about the same as delivery. Cut-to-size pieces are made for you, so they cannot be returned.

Frequently Asked Questions
What is the difference between 20mm and 30mm?
It is a look choice. 30mm has a thicker edge and a more substantial look, and is heavier to lift. Both thicknesses suit any hearth. As always, check with your installer in case there is a specific reason to choose differently. 30mm is made in 1200 × 900 and 1500 × 900 only.
How heavy is a 1200 × 900 slate hearth?
61 kg at 20mm and 91 kg at 30mm. A 1500 × 900 weighs 76 kg (20mm) or 113 kg (30mm), a 900 × 900 45 kg and a 900 × 600 30 kg. Every size is a two-person lift.
How much is delivery and how long does it take?
£78 per order to England and Wales, however many slabs up to 1200 × 900 you order, or £130 if the order includes a 1500 × 900. Express is £96 or £160. Delivered kerbside on a pallet in 3–5 working days. Scotland, Northern Ireland and the islands are quoted by phone on 01908 46 46 56.
Can I collect it?
Yes, free from our Milton Keynes workshop (MK8 8DD). Book it at checkout; it is usually ready the next working day and we email you when it is. Collection from Colchester (CO6 2JX) is arranged by phone on 01908 46 46 56, to confirm availability and any handling fee.
Does a slate hearth need sealing?
No, you can fit it raw. Sealing deepens the colour from graphite grey to black. Oil it yourself, or add Deep Clean & Seal and it arrives cleaned and sealed with Stovax Dressing Oil, ready to fit. Allow one extra working day for the oil to dry.
What is the credit card test?
Every slab must let a standard credit card slide across the riven surface without catching. It means the face is flat enough for a stove to sit level without rocking. Slabs are also calibrated to ±1mm, with 90° machine-sawn edges.
What happens if my hearth cracks?
Fit it within 14 days of delivery. If it cracks in that time, we replace it free. Cut pieces are included. Full crates are not covered.
Can I return it?
Yes, within 30 days of delivery on stock sizes, unused and in the original packaging, with no restocking fee. You arrange and pay the return pallet, which costs about the same as delivery. Cut-to-size pieces are made for you, so they cannot be returned.
What other sizes does this come in?
This riven slate hearth is also available in Brazilian Black Riven Slate Hearth — Full Crate, all in the same riven finish and 30mm thickness. (Automatically generated from current sizing — always up to date.)