Is there a black Kota stone?

Not really — Kota limestone's natural colour range is blue-grey, green and brown, not black. If a project genuinely needs a black natural stone floor, we supply basalt instead, which is a harder, different rock that goes to a true jet-black polish. Some suppliers stretch the name "Kota" to cover it; we'd rather tell you plainly which stone you're actually getting.

Is basalt the same as black granite?

No, though they compete for the same look. Basalt is a fine-grained volcanic rock with almost no visible crystal structure; black granite is coarser-grained and speckled up close. Basalt is generally the more affordable of the two for an equivalent black, polished floor.

The hardest stone we supply

Black Basalt Stone

Volcanic rock from the Deccan Traps — dense, non-porous and close to three times the compressive strength of Kota. Where a floor or paving has to take genuine punishment, basalt is the answer.

The material

About Black Basalt Stone

Basalt is igneous — lava cooled fast enough to form an extremely fine, tight grain with almost no bedding planes. India sits on the Deccan Traps, one of the largest basalt formations on earth, and Indian basalt is now a global reference material for heavy-duty paving.

If you searched for "black Kota stone," this is worth reading first. Kota limestone itself does not come in a true black — its natural palette is blue-grey, green and brown. What we supply for a genuinely black natural stone floor is this basalt: a different, harder rock entirely, not a colour grade of Kota. It costs more than Kota per square foot, but if black is the requirement, this is the honest answer rather than a stretch of the word "Kota."

The numbers are the point. Compressive strength runs 1,500 to 3,000 kg/cm², density 2,800–3,000 kg/m³, absorption under 0.5%. It does not stain, spall in frost, soften near salt water or fade. Airport aprons, city plazas, bus stations and pool decks are all natural basalt applications.

Visually it runs from jet black to charcoal, and the finish changes the reading completely. Flamed is matte charcoal with a high-grip face. Honed is a flat mid-grey-black. Polished goes to a near-mirror black that rivals imported granite at a fraction of the price.

Rock-faced and flamed get confused constantly. Rock-faced is split and chiselled — sharp facets, strong directional grain, and what most people mean by a stone-clad feature wall. Flamed is thermal: the surface is heated until the outer crystals spall off, leaving a fine granular texture with no facets. Rock-faced is for elevations you look at; flamed is for floors you walk on. The photographs here are our own stock — rock-faced and flamed both.

It is the most expensive material on our list and it should be — it saws slower, costs more in consumables and yields less per block than a sedimentary stone. Specify it where the loading or the lifespan justifies it, and nothing else in the Indian range comes close.

Available finishes

FlamedHoned finishMirror polishBush-hammeredSandblastedLeather / lapatroRock facedSawnTumbled cobbles

Nine black basalt finish samples photographed side by side — sandblasted, bush-hammered, flamed, honed and polished

The same basalt, nine ways. Texture decides the colour far more than the block does — worked faces read pale grey, sawn and polished faces read black.

Black Basalt Stone — The hardest stone we supply

Black basalt, flamed finish — fine granular texture, no facets

Black basalt, leather finish — soft dimpled matte, jet black

At a glance

Stone familyIgneous / basalt

ColourJet black to charcoal grey

Thickness15 – 100 mm

Finishes9 available

Cut to sizeYes, to drawing

Random slab, 20 mmfrom ₹84/sq ft — rate list

DispatchPan-India road & container export

Where it works

Typical applications

Commercial and public plazas
Airport, station and transit paving
Heavy-duty driveways and forecourts
Pool decks and coastal projects
Contemporary interior floors
Facade cladding
Kitchen counters and vanities
Kerbs, channels and cobbles

Request a quote for Black Basalt Stone

Technical

Properties

Stone typeFine-grained igneous volcanic rock (Deccan Traps)

ColourJet black to charcoal grey; deepens when polished

Density2,800 – 3,000 kg/m³

Compressive strength1,500 – 3,000 kg/cm² (150 – 300 MPa)

Modulus of rupture200 – 250 kg/cm² (20 – 25 MPa)

Water absorptionUnder 0.5%

Mohs hardness6

Frost & salt resistanceExcellent — suitable for coastal and de-iced surfaces

Acid / alkali resistanceExcellent — chemically inert silicate

Slip resistanceVery high when flamed or bush-hammered

Grooved and diamond-cut

Cut on the diamond saw, then grooved.

Every flat basalt face we sell starts on the diamond saw. The blade leaves a true, flat, closely gauged surface — that is what "diamond cut" means in this trade, and it is the face that every later treatment is worked onto. Left as it comes off the saw it is a clean mid-grey-black with faint blade travel across it.

Grooving is the anti-skid answer for basalt. Parallel grooves are cut into the sawn face at a set pitch, deep enough to break the water film and give a boot or a tyre something to bite on. Unlike flaming, grooving does not lighten the colour — the face stays black and the grip comes from the geometry, not from a roughened surface. It is what we supply for ramps, wet approaches, pool surrounds, loading aprons and any external stair that has to stay safe in the monsoon.

The same saw cuts pattern work. Crossed arcs, radial sweeps and border grooves are all cut on the machine to a drawing, not chased by hand, so every piece in a run matches. On a large slab a swept diamond cut reads as a single deliberate line across the floor rather than as a texture — worth specifying where the stone itself is the feature.

Groove depth, pitch and direction are all to order. Tell us whether the piece is a tread, a ramp or a floor and we will set the pitch to suit; the standard is a fine pitch on treads and a wider, deeper one on vehicle ramps.

Close-up of a diamond-cut black basalt slab with crossed arc grooves across the face

Pattern work cut on the machine — crossed arcs across a full slab face. Cut to a drawing, so every piece in a run matches.

Stacks of grooved black basalt slabs at the yard, anti-skid grooves running along the face

Grooved stock at Amarpura. The grooves run the length of the piece; pitch and depth are set to the job.

Grooved and diamond-cut basalt slabs beside the cutting machine at our unit

On the line at our unit. Grooving is a machine pass on the sawn face, not a hand-worked finish.

In the yard

What basalt looks like laid.

All our own stock and our own yard at Amarpura — crazy paving, steps, cladding and finish samples photographed as they were laid, not rendered.

Crazy paving

Irregular flags with a honed face, sorted so the pieces close up with an even joint. Garden paths, courtyards and terraces where a grid would look too formal.

Basalt steps with rock-faced risers and sawn treads, paving laid around them

Steps and treads

Sawn treads over rock-faced risers — the combination most people ask for. The riser gives the shadow line; the tread stays flat and safe underfoot.

Yard display wall of rock-faced basalt ledgestone cladding beside brick-pattern panels

Cladding patterns

Rock-faced ledgestone in a running bond, alongside brick-pattern and plain panels. Built in the yard so you can see the shadow a real elevation throws.

Rough black basalt blocks in the yard at sunset, buff weathered crust over a black core

Raw blocks

Blocks as they arrive, buff-weathered outside and black through the core. Everything on this page is sawn out of stock like this.

Dark bush-hammered basalt tiles laid against pale sandblasted basalt tiles

Two finishes, one stone

The dark centre and the pale surround are the same basalt. Texture is what changes the colour, which is why a sample has to be in the finish you are actually buying.

Four sandblasted black basalt strips laid on a plinth, pale grey faces with black edges

Sandblasted strips

Sandblasted faces with the black sawn edge still showing. The pale grey face is the abraded surface, not a different block.

Every photograph on this page is our own stock at Amarpura, Ramganjmandi. Ask for a sample in the finish you intend to buy — basalt changes more between finishes than any other stone we sell.

Sizes