Onyx Bianco Extra (also Onice Bianco Extra, Bianco Onyx Extra, Iran White Onyx Extra or White Onyx Premium) is the premium Extra grade of the Iranian Onyx Bianco — a particularly selected, almost vein-free pure white variant with only the subtlest warm cream and ivory accents and maximum translucency. Highly translucent — the exclusive first choice for backlit wall claddings, premium feature walls, washstand tops, bar counter fronts and prestigious decorative interior architecture with a luxuriously luminous, almost candle-like lighting effect.
“Extra” denotes, in the stone trade, a selected premium quarry quality — not a material variety in its own right, but the highest-grade block selection of the Onyx Bianco family of Iranian origin, with the purest white tonality and the most minimal vein marking. Petrographically a chemically sedimentary calcite onyx with a banded layered structure and exceptionally high translucency.
Other trade names: Bianco Onyx Extra, Onice Bianco Extra, RO-10-042
About Onyx Bianco Extra
Onyx Bianco Extra is the selected premium grade of the Iranian Onyx Bianco — the “Extra” addition in the trade name denotes, in the stone trade, a particularly selected quarry quality with the purest white tonality, the most minimal vein marking and the most even mineral distribution. Within the Iranian onyx family, Onyx Bianco Extra thus represents the highest quality level of the white onyx grade — blocks with an almost completely homogeneous white appearance and exceptional translucency, reserved for the most demanding design applications. The trade names used in parallel — Onyx Bianco Extra, Onice Bianco Extra, Bianco Onyx Extra, Iran White Onyx Extra and White Onyx Premium — are synonymous designations from the Italian, international and English-language marketing of this premium grade.
Geologically, Onyx Bianco Extra, like all onyx varieties, is a chemical sedimentary stone formed by the slow precipitation of calcium carbonate from supersaturated calcareous spring or cave waters — comparable to stalactites in dripstone caves. This layer-by-layer formation explains the characteristic banded structure of onyx and its high translucency: the material consists of parallel-grown calcite crystal layers that let light through unusually deeply and softly. The premium “Extra” grade represents particularly purely grown onyx zones with the most minimal colouring mineral fractions — the light white to creamy ivory tonalities result from an exceptionally pure calcite composition. The availability of the Extra grade is correspondingly limited compared with the standard variant of Onyx Bianco.
Visually, Onyx Bianco Extra is defined by an exceptionally elegant, almost ethereal material signature. The ground tone is an almost pure, milky cream-white to ivory white with a delicate translucency and only the subtlest warm cream and ivory accents. Compared with the standard grade of Onyx Bianco, the Extra grade shows considerably fewer visible vein courses and cloudings — the almost completely homogeneous white tonality is the defining characteristic of this premium class. The layered banded structure typical of onyx is recognisable, but in the Extra grade particularly delicate and fine. The slab variation is decidedly low by onyx standards — the premium selection ensures a constant pure appearance across several slabs, which makes Onyx Bianco Extra one of the few onyx grades that can be considered for large-area homogeneous installations.
The outstanding property of Onyx Bianco Extra is its exceptional translucency — precisely because of the high purity of the calcite composition, the stone lets light shine through in a particularly soft, candle-like manner. Backlit, the stone shows a warm, soft, almost porcelain-luminous inner glow that makes the delicate, subtle cloudings appear as frozen movements of light. This exceptional translucency makes Onyx Bianco Extra one of the most sought-after materials for luxurious backlit interior architecture — top-class hotels, exclusive private residences, lounge and bar areas, spa facilities and yacht interiors use Onyx Bianco Extra as backlit wall claddings, counter fronts, illuminated washstand tops and wall accents. Compared with warm Iranian onyx variants (Vaniglia, Sultan, Cappuccino), the light through Onyx Bianco Extra appears particularly cool, pure and neutral.
Technically, Onyx Bianco Extra, like all onyx varieties, is a comparatively soft and sensitive material — considerably softer than marble, with high acid sensitivity, low abrasion resistance and limited load-bearing capacity. The water absorption of Onyx Bianco is around 0.95 %. Fabrication is traditionally carried out in thicknesses of 2 cm, frequently also in thinner thicknesses of 1 cm to 1.5 cm for backlit applications, since a lower material thickness increases light transmission. Like all carbonate rocks, Onyx Bianco Extra is acid-sensitive and reacts to citric acid, vinegar or acidic cleaners with matt etching — a sensitivity that can become visually particularly conspicuous through the light, pure white ground tone.
In interior construction, Onyx Bianco Extra is a decorative premium statement material for the highest design ambitions where a pure white translucent material effect is wanted. Classic applications are backlit wall claddings in hotel lobbies, restaurants and exclusive living spaces; bar counters and counter fronts with backlighting; washstand upstands and illuminated mirror surfaces in luxurious bathrooms; decorative column claddings; free-standing wall panels with staged lighting; table and console tops; lampshades. The premium selection, with its decidedly homogeneous appearance, makes Onyx Bianco Extra one of the few onyx grades that can be considered for large-area wall claddings where an even appearance is wanted — most other onyx variants show such strong slab variation that they are less suitable for such applications. The cool white tonality harmonises particularly with clear white, with light timber fittings in pale oak or birch, with nickel, chrome and silver accents, with exposed concrete and with reduced neutral wall colours — a stone for modern, urban-luxurious interior architecture with a light-filled atmosphere.
In stock
Current availability from our warehouse.
1 slab in stock · plus 1 block
Thicknesses: 2 cm · Finishes: Polished · Available as: Slabs
Onyx Bianco Extra is available in a range of finishes. The finish affects appearance, feel and the care it needs.
Polished
Polishing is the preferred finish for onyx — the mirror-smooth surface brings out the material's varied colour character in full. The highest possible colour intensity and deep light reflection. Onyx is acid-sensitive and softer against scratches than marble — recommended for wall cladding and designed visible surfaces, less so for worktops.
Care & fabrication
Onyx Bianco Extra is a sensitive premium statement material and requires careful maintenance. Because of its carbonate composition the stone is acid-sensitive — acidic foods such as lemon juice, vinegar, wine, cola and fruit juices, as well as acidic cleaners, cause matt etch marks even after brief contact, and these become visually particularly conspicuous on the pure white premium ground tone. For daily cleaning use exclusively warm water with a pH-neutral stone cleaning agent; aggressive household cleaners, abrasive sponges or microfibre cloths with a scouring action must be strictly avoided. Take up spilt acidic liquids immediately with clear water. A professional impregnation after laying, and then every 1 to 2 years, is strongly recommended — it reduces the absorption of pigments (red wine, coffee, olive oil) and protects the polished surface against water droplet rings, which become particularly conspicuous on the light tonality. In bathrooms it is advisable to squeegee off water droplets after showering, since standing water on non-impregnated areas can lead to discolouration in the long term. For backlit wall claddings the care requirement is low — occasional dusting and gentle wiping with a damp cloth is sufficient. For washstand tops and bar counters, gentle cleaning agents and the immediate removal of all soiling should be standard.
Frequently asked questions
What distinguishes Onyx Bianco Extra from Onyx Bianco?
Both come from the same Iranian onyx quarries and are technically identical materials. Onyx Bianco Extra is the premium grade with the purest white tonality, the most minimal vein marking and the most even mineral distribution — blocks with an almost completely homogeneous white appearance. Onyx Bianco (the standard grade) shows somewhat more visible movement and occasional finer cloudings or vein zones. Both have the same technical properties (the same acid sensitivity, the same water absorption, the same hardness) — the “Extra” classification concerns the visual purity alone. Onyx Bianco Extra is higher in price and more limited in availability.
What does the designation “Extra” mean?
The marketing addition “Extra” denotes, in the stone trade, a particularly selected premium quarry quality — blocks with the highest visual purity, the most minimal impurities and the most even mineral distribution within a stone family. The classification is made by the supplier or the stonemason on the basis of the visual quality of the blocks and reflects a selected top quality, not a different material variety. Onyx Bianco Extra, Onice Bianco Extra, Bianco Onyx Extra, Iran White Onyx Extra and White Onyx Premium are synonymous trade names for this premium selection.
Is Onyx Bianco Extra suitable for large-area wall claddings?
Yes, particularly well. Because of the premium selection, with its decidedly homogeneous appearance, Onyx Bianco Extra is one of the few onyx grades that can be considered for large-area wall claddings where an even appearance is wanted — most other onyx variants show such strong slab variation that they are less suitable for such applications. For larger orders, a prior slab viewing is recommended in order to verify the visual consistency of the delivery.
Can Onyx Bianco Extra be backlit?
Yes — and backlighting is the most spectacular application of this premium grade. The crystalline layered structure of the stone lets light pass through the material in a warm, soft, almost porcelain-luminous glow and makes the delicate, subtle cloudings particularly impressively visible. Compared with warm Iranian onyx variants, the light through Onyx Bianco Extra appears particularly cool, pure and neutral, which makes the stone particularly attractive for modern, urban-elegant design concepts. For backlit installation, thinner slab thicknesses (1 to 1.5 cm) are usually chosen.
Is Onyx Bianco Extra suitable for floor surfaces?
Not in heavily frequented areas. Onyx is a comparatively soft and acid-sensitive material and develops visible traces under intensive foot traffic. In prestigious areas with moderate frequency, such as private living rooms, exclusive bedroom areas or salons in top-class hotels, use as a floor tile is possible. For entrance halls, restaurants or other heavily frequented areas, denser hard rocks such as marble, quartzite or granite are the suitable choice.
Is Onyx Bianco Extra suitable for kitchen worktops?
Only to a limited extent. The acid sensitivity towards lemon juice, vinegar, wine and cola, as well as the lower hardness compared with marble and granite, make Onyx Bianco Extra less than ideal for family kitchens with a demand for robustness. On the pure white premium ground tone, acid-induced etch marks are visually particularly conspicuous. In very well-kept design kitchens in which the appreciation of the material is explicitly based on the naturally ageing character of a premium onyx, use as a statement island or a decorative counter front is possible; for intensive everyday loads, acid-insensitive hard rocks are recommended.
What does Onyx Bianco Extra cost?
The price depends on the batch, thickness, surface finish and fabrication — with natural stone there is no serious flat rate per square metre. Business customers see prices once their B2B account is activated; private customers receive a complete quote through a fabricator near them.
