Brazilian black honed slate hearth slab, 20mm, calibrated flat with an even matte honed face

Brazilian Black Honed Slate Hearth

£190.00 inc. VAT

★★★★★ 4.84/5 · 694 reviews✓ In stock
Container direct ⓘ
Imported direct from the quarry in Brazil and held in our own yard. No middleman and no showroom markup.
Calibrated flat ±1mm ⓘ
Machined flat and calibrated to ±1mm. A honed face has no cleft and no ridges, so the slab beds down without packing and your stove does not rock.
14-day crack guarantee ⓘ
Fit it within 14 days of delivery. If a single slab cracks in that time, we replace it free. Terms ➔

Not the size you need?

We cut honed slate to your exact size, up to three matching pieces from one slab. From £285.

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.

Overview

Container-direct Brazilian black honed slate hearths, supplied by Bluesky Stone Direct from Milton Keynes and Colchester. Three stock sizes, 20mm calibrated throughout, all from the same quarry, all held in stock.

Honed, not riven — and that is the whole point. The face is machined flat and satin-smooth: no cleft, no ridges, no undulation. If you want the split natural texture instead, buy the riven hearth. We would rather send you there than sell you the wrong surface.

What customers say

4.84 out of 5 from 694 reviews, collected by Judge.me.

★★★★★
Received an incorrect item to begin with but this VERY QUICKLY and SUPERBLY put right by one of the company owners (Leo) who personally drove down to me in London the next day to deliver the correct replacement - this was probably the best customer service I've ever received, which I'm very grateful for. A highly recommended company!
Martin Boronte · Honed Slate Hearth · September 2026
★★★★★
One word - FANTASTIC !! A very simple but well crafted website made ordering a straightforward process. Communication from Bhey at Bluesky Stone was excellent and customer care was superb. I collected my order and Brian at the workshop was just wonderful. I was late but nothing was too much trouble. He carefully loaded my stone in through the boot of my car helping me make it secure and even went the extra mile by giving me a bottle of cold refreshing water for my long journey home. Fantastic
David Hughes · Standard Riven Slate Hearth · October 2026
★★★★★
Delighted to find a local company that can supply first class premium product at a competitive price. Easy to order on line using their website and collection notification and process first rate. Highly recommended!
KLL · August 2026

Read all 694 reviews ➔

How it arrives

  1. 1 · You order
  2. 2 · We book your pallet
  3. 3 · Delivered kerbside

Kerbside on a pallet. We recommend a two-person lift.

Specification, sizes and weightsSlip rating, strength, sizes and weights

Stock sizes, weights and crate quantities

Size Thickness Weight Slabs per crate
1200 × 900 20mm 61 kg 15
1500 × 900 20mm 76 kg 12
1200 × 1200 20mm 81 kg 10

All slabs are calibrated to ±1mm with clean 90° machine-sawn edges, no chamfer. Want dressed edges? Cut to Size pieces come with the sides honed and the top edge eased. Honed is made in 20mm only. Every slab is a two-person lift and is delivered kerbside on a pallet.

Why honed has no Standard or Premium grade

On riven slate we hand-sort by tone, because a split face varies from slab to slab. Honing removes that variable — the diamond process takes every slab to the same flat satin surface and the same graphite tone. There is one grade because there is nothing left to sort, and one price for each size.

The face still carries soft, cloud-like grain movement. That is the internal structure of the stone exposed by the hone, not a fault, and it is why no two hearths read identically.

On every slab

  • 14-Day Crack Guarantee. Fit your hearth within 14 days of delivery. If a slab cracks in that time, we replace it free.
  • Calibrated flat. ±1mm across the slab, so the hearth beds down without packing and does not rock under a stove.
  • Container-direct pricing. Brazilian slate bought by the container, not through a UK middleman.
  • Samples. Up to two free samples for a flat £5 delivery. Order a sample before committing to a full slab.

Technical specification

  • Thickness: 20mm calibrated, ±1mm
  • Surface: super-flat satin hone, zero cleft, with soft cloud-like grain movement
  • Edge: clean 90° machine-sawn as standard, no chamfer
  • Slip resistance: PTV 54 dry / PTV 38 wet — low slip risk
  • Flexural strength: 19.6 MPa after 48 freeze-thaw cycles
  • Water absorption: under 0.50% — high frost resistance
  • Colour: graphite grey to black in its raw state. Sealing takes it to a deep, velvety charcoal.
  • Suitability: designed for the weight and radiant heat of a wood-burning or multi-fuel stove. Not for direct flame contact.

How it arrives

  • Unsealed — included. Delivered in 3–5 working days.
  • Deep Clean & Seal — £30. Deep-cleaned to remove quarry dust and fine hone slurry, then two coats of Stovax Dressing Oil. This is what takes the stone from graphite to charcoal. 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 £300 including the slab. Delivered within 14 days, or 7 on Priority.

Delivery and returnsCosts, collection, 14-day returns

Delivery and collection

  • Delivery to England and Wales is priced at checkout — no quote needed, and charged per order rather than per slab.
  • Scotland, Northern Ireland and the Islands — costs vary by postcode, so we quote individually. Call 01908 46 46 56 or email sales@blueskystone.com.
  • 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.
  • Delivered kerbside by pallet via a nationwide carrier.

Buying by the crate?

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

14-day returns on stock sizes

Changed your mind? Tell us within 14 days of delivery, then send the slab back within a further 14 days. No restocking fee. We refund the slab and the original delivery, up to our Economy rate. You arrange and pay the return pallet, which costs about the same as delivery. Sealed slabs can come back too; the sealing charge is not refunded. Cut-to-size pieces are made for you, so they cannot be returned. Returns in full.

Arrived damaged?

Tell us within 48 hours of delivery and we replace it free, delivery included. Damage policy ➔

Questions before you order
Does honed slate come with a chamfered edge?
No. Honed slabs from stock come with clean 90° machine-sawn edges and no chamfer. If you want dressed edges, choose Cut to Size: your pieces come with the sides honed and the top edge eased.
Is honed slate made in 30mm?
No, honed is made in 20mm only. If your installer has specified 30mm, our riven and brushed slate hearths come in 30mm.
How heavy is a honed slate hearth?
1200 × 900 weighs 61 kg, 1500 × 900 weighs 76 kg and 1200 × 1200 weighs 81 kg, all at 20mm. Every size is a two-person lift.
How much is delivery and how long does it take?
One charge per order to England and Wales, however many slabs you order, shown beside the price and confirmed at checkout. 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 honed slate hearth need sealing?
No, you can fit it raw. Sealing takes it from graphite grey to a deep charcoal. 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.
Will I get a photo of my slab before it is sent?
Not on honed slabs from stock, because every honed slab has the same flat face and tone. Cut to Size orders in honed do include photos of your pieces before they are packed.
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. Tell us within 14 days of delivery, then send it back within a further 14 days. No restocking fee, and we refund the original delivery up to our Economy rate. You arrange and pay the return pallet, which costs about the same as delivery. Sealed slabs can come back, but the sealing charge is not refunded. Cut-to-size pieces are made for you, so they cannot be returned.
What other sizes does this come in?
This honed slate hearth is also available in Brazilian Black Honed Slate Hearth — Full Crate, all in the same honed finish and 20mm thickness. (Automatically generated from current sizing — always up to date.)