Onyx is the only stone people buy for what happens when you put a light behind it.
That single fact changes the whole specification. Everything that matters about a backlit onyx panel — translucency, banding, structural integrity, the invisibility of the light source — is decided before the slab leaves the factory, and most of it cannot be fixed afterwards.
Indian Green Onyx — and the mis-sell to avoid
Verified origin: pocket mines around Udaipur, Rajasthan.
Indian Green Onyx is a translucent banded stone in deep bottle-green through jade, with cream and white veining running in parallel bands. Backlit, it glows a saturated green with the banding reading as light and dark strata.
The name to use is "Indian Green Onyx, Udaipur". Say it in full, every time. Pakistani onyx is sold widely and sometimes presented as Indian; the two are genuinely different in banding character and in supply reliability. If you are specifying Indian material, the paperwork should say so and the origin should be traceable.
Udaipur onyx comes from small pocket mines rather than large industrial quarries. This has a practical consequence you should plan for: volume is limited and block sizes are modest. A project needing 200 m² of matched onyx is a serious sourcing exercise, not a phone call.
The other onyx colours
Honey / amber onyx — the classic warm translucent stone, golden-caramel with cream banding. This is what most clients picture when they say "backlit onyx". Indian supply exists but the world market for honey onyx runs heavily on Iranian, Turkish and Pakistani material. We will source it to specification and describe its origin accurately rather than putting a foreign stone on an Indian invoice.
White onyx — pale ivory with grey-gold veining. Backlit it produces a soft even glow rather than a coloured one, which makes it the choice for reception desks and bar fronts where the light is meant to be architectural rather than decorative.
For a genuinely Indian white with high visual value, also consider Makrana White Marble — not translucent in the same way, but the only Indian stone with GHSR heritage status. See Makrana White Marble: The Stone That Built the Taj Mahal.
Specifying for backlighting
Translucency is a property of the block, not the stone
Two slabs of the same onyx from different blocks can transmit light very differently. Never specify onyx from a photograph. Ask for the actual slab to be photographed with a light behind it, on a dark background, at the thickness you intend to use.
Thickness
20 mm is the usual backlit thickness — thick enough to be structurally viable with a backing, thin enough to transmit. Below 20 mm transmits more but requires a laminated backing, always. 30 mm transmits noticeably less and is generally used where the panel must be self-supporting.
Decide with a physical test at the exact thickness. The difference between 18 mm and 20 mm is visible.
Resin, mesh and lamination
Onyx is fractured stone. Almost all commercial onyx is resin-treated and mesh-backed. This is normal, necessary and must be disclosed — because it changes what happens under light.
- Fibreglass mesh on the back becomes visible as a grid when backlit. For backlit applications the mesh must be either omitted (with the slab laminated instead) or specified as a low-visibility type, and the result must be tested with light.
- Resin fill in fissures reads differently from stone under light — sometimes as a bright line, sometimes as a dark one.
- Lamination to glass or to an aluminium honeycomb panel is the standard solution for large backlit panels. Glass lamination adds strength and lets you go thinner; honeycomb keeps weight down on a suspended installation.
Ask the supplier: how is this slab backed, and can you send me a backlit photograph of the actual piece?
Bookmatching
Onyx is nearly always bookmatched — consecutive slabs opened like a book so the veining mirrors across the joint. For a four-way or six-way match, you need consecutive slabs from one block, sequenced and numbered, and you need them all in the same container.
Order the whole match at once. A bookmatch completed from a second shipment is not a bookmatch.
The light source
This is where most backlit onyx installations disappoint, and it is not the stone's fault.
- LED panel behind, not LED strip. A strip produces visible hot spots and dark bands. An edge-lit diffusion panel or a dense LED sheet produces even light.
- Cavity depth matters. Too shallow and you see individual diodes. Ask your lighting designer for the minimum cavity depth for the panel type — it is usually more than the joiner wants to give you.
- Colour temperature changes the stone. Green onyx under warm white reads olive; under neutral white it reads jade. Test with the actual fitting.
- Heat. Use fittings that run cool and allow ventilation in the cavity. Heat and resin-filled stone are not friends over years.
- Access. Plan how a failed driver gets replaced without dismantling the stone.
Where backlit onyx belongs
Hotel and restaurant bar fronts — the highest-value application, and the one where onyx earns its cost. Reception desks — front panel backlit, top usually a harder stone. Feature walls in lobbies, spas and residential entrance halls. Bathroom vanity fronts and shower niches — moisture is the constraint; specify accordingly. Ceiling panels — spectacular and structurally demanding; laminate to honeycomb.
Where it does not belong: floors, worktops, external applications, and anywhere it will be knocked. Onyx is a soft, fractured, acid-sensitive stone. It is a light fitting that happens to be geological.
Market notes
UAE. The strongest market in the world for backlit onyx, by a wide margin. Hotel, retail, villa and palace work all use it heavily, and Gulf specifiers are experienced buyers who will ask exactly the right questions about mesh visibility and cavity depth. Expect a physical backlit mock-up before approval.
United States. Commercial hospitality and high-end residential. US fabricators are cautious about onyx and will want the backing method specified in writing.
Packing — onyx is the fragile one
Resin-and-mesh onyx breaks in transit more readily than any other stone in a stone exporter's catalogue. Specify:
- Vertical crates, never flat stacking
- Full-face foam protection, not just corners
- No steel banding in contact with the face
- Bookmatched sets crated together and marked as a set
- Desiccant inside the wrap
Details in Sea Packing for Natural Stone: How India Ships It Intact.
What to ask before you order
- Actual backlit photograph of the actual slab, at your thickness, on a dark ground.
- Backing method — mesh type, resin, or lamination — and whether the mesh reads under light.
- Bookmatch sequence confirmed, numbered, and shipped together.
- Block size and yield — how many matched slabs exist from this block, total.
- Origin in writing — for green onyx, "Indian Green Onyx, Udaipur", not "onyx".
- Repeat availability — usually none. Buy the whole job at once.
What Gemarix does differently
We name the source. Indian Green Onyx is Udaipur pocket mines, and we say so because the mis-sell risk in this material is real. Where we source a colour that is not Indian, we tell you where it is from rather than letting an Indian invoice imply an Indian origin.
And we will send you a backlit photograph of the actual slab before you commit, because nobody should buy onyx from a daylight image.
Frequently Asked Questions
Where does Indian Green Onyx come from?
From pocket mines around Udaipur in Rajasthan. Because it comes from small pocket mines rather than large industrial quarries, block sizes are modest and volume is limited, so a large matched order is a sourcing exercise rather than a phone call.
What thickness should backlit onyx be?
20mm is the usual backlit thickness: thick enough to be structurally viable with a backing, thin enough to transmit light. Below 20mm transmits more but always needs lamination. 30mm transmits noticeably less. Decide with a physical test at the exact thickness, because the difference between 18mm and 20mm is visible.
Does the mesh backing show when onyx is backlit?
It can. Almost all commercial onyx is resin-treated and mesh-backed because the stone is naturally fractured. Fibreglass mesh reads as a grid under light, so for backlit work the mesh must be omitted in favour of lamination, or specified as a low-visibility type and tested with light before you commit.
Can backlit onyx be used for worktops or floors?
No. Onyx is soft, fractured and acid-sensitive. It belongs on bar fronts, reception desks, feature walls, vanity fronts and ceiling panels. It is a light fitting that happens to be geological, not a working surface.
How should backlit onyx be lit?
Use an LED panel behind the stone rather than a strip, because a strip produces visible hot spots and dark bands. Allow adequate cavity depth so individual diodes do not read through, use fittings that run cool with ventilation, and test the colour temperature, since green onyx reads olive under warm white and jade under neutral white.