CTX BasicKeramik® RES Onice Avorio belongs to the ROSSITTIS house brand CTX BasicKeramik® — a porcelain line of our own conception that we develop together with selected Italian premium ceramics manufacturers and offer under our own brand name. The “RES” marking in the design name identifies the Italian upstream manufacturer. CTX BasicKeramik® stands in the same house brand family as our CTX BasicQuarz® (engineered quartz).
The design model — Onice Avorio (Italian for “ivory onyx”) — is among the most sought-after translucent building stones in architectural history. In natural stone terms, Onice Avorio is a “calcite onyx” or “marble onyx” — a stone formed by hydrothermal calcium carbonate precipitation in karst caves, NOT to be confused with the mineralogically related chalcedony onyx (on an SiO₂ basis) of the jewellery industry. Geologically it is a calcitic sinter stone: in cave systems, mineral-bearing water drips down walls and ceilings, crystallises in cyclical layers into a solid calcite aggregate and in doing so encloses subtle impurities of iron oxides, clay particles and organic material. The characteristic horizontal banding is the geological record of these precipitation cycles — each layer represents a different phase of growth with a different mineral composition.
Classic Onice Avorio deposits are found in Iran (particularly in Yazd province — the world's most important source of onyx), in Pakistan (ivory onyx from Balochistan), Mexico (the classic “Mexican onyx”) and in part in Italy (smaller Alpine onyx occurrences). The characteristic warm creamy ivory ground tone, the translucency and the delicate horizontal layering have made Onice Avorio one of the most sought-after materials for backlit wall claddings, vanity tops, reception areas and sacred architecture since antiquity. Genuine Onice Avorio is, however, an extremely care-intensive material: highly acid-sensitive (calcite chemistry), prone to scratching (Mohs hardness 3), sensitive to water, and strongly limited in stock availability.
In the slab picture, CTX BasicKeramik® RES Onice Avorio shows an authentic reproduction of this premium onyx character: a soft, warm ivory-cream ground picture that looks almost translucent depending on how the light falls — as though the material scattered light rather than merely reflecting it. Across this ground tone run gently flowing horizontal bands of movement in delicate golden-honey, cream-grey and ivory tones — reproductions of the original geological layering. In places the bands condense into more powerful wave zones with a somewhat more dramatic depth of effect, then continue softly and in a controlled way. The impression is gently luxurious, softly flowing and atmospheric — a completely different material language from the sharp vein patterns of the Calacatta marbles or the structural conglomerates of Ceppo di Gré.
It is precisely this design particularity that is the strength of the material. RES Onice Avorio does not compete with dramatic marble-look designs; it works as an atmospheric, luxurious stage with an almost light-permeable effect. In backlit wall claddings, reception desks, vanity tops, bar counters and prestige bathrooms, the stone develops a warm, luminous mood that hardly any other material achieves. Combined with warm timber (walnut, olive, cedar), brushed brass, bronze, subdued light and calm architectural backgrounds, the warm ivory pictorial idea develops a classically luxurious atmosphere.
Technically it is a fully sintered large-format porcelain. Mineral raw materials (natural clays, feldspars, quartzes and pigments) are pressed under high pressure into a large-format slab and sintered at temperatures above 1,200 °C. The result is a chemically non-reactive, almost pore-free ceramic material with a water absorption of < 0.1 %. The material properties: full UV stability, acid resistance, heat resistance, scratch resistance (Mohs hardness 7–8), frost resistance and food safety.
In direct comparison with genuine Onice Avorio, the porcelain reproduction offers concrete advantages: full acid resistance (genuine onyx, as a calcite aggregate, is extremely acid-sensitive — lemon, wine and tomato sauce leave etch marks immediately), scratch resistance (genuine onyx has a Mohs hardness of 3 and is extremely prone to scratching), full heat resistance, insensitivity to water (genuine onyx can develop discolouration on contact with water), a precisely reproducible look (genuine onyx varies strongly from block to block) and full suitability for exterior use. The one technical property the porcelain does not reproduce is the genuine translucency of the natural material for backlit applications — here, for the highest demands in staging light, genuine onyx remains the more suitable material.
At ROSSITTIS we currently carry CTX BasicKeramik® RES Onice Avorio as 22 large-format slabs in 12 mm thickness with polished and naturale matt finishes. On request we produce from them wall claddings, vanity tops, reception desks, bar counters, table surfaces, floor tiles, pool surrounds, exterior façades and project-specific bespoke cuts.
For anyone comparing RES Onice Avorio with other materials: the stylistic model is genuine Onice Avorio from Iran, Pakistan or Mexico — geologically authentic and translucent, but expensive, extremely care-intensive and suitable only for selected applications. Among the porcelain competition, Laminam Cristallo Bianco, Lioli Porcelain onyx versions, the Florim onyx look and Atlas Concorde Marvel Onyx offer similar designs. Among the polyester engineered quartz materials, Caesarstone Lioli Porcelain Supernatural onyx, Silestone Eternal Calacatta Gold and Compac onyx versions offer comparable ivory pictures — with limited heat resistance and absent UV stability.
Our honest assessment: CTX BasicKeramik® RES Onice Avorio is a distinctly successful choice for projects that want to combine the luxurious ivory onyx picture with the full robustness of porcelain. Anyone who needs genuine translucency for backlit wall claddings should reach for genuine onyx — and accept the corresponding care and price implications. But anyone who wants the warm, ivory, flowing onyx picture in an easy-care, heat- and acid-resistant large-format quality — while using the economically attractive calculation of a ROSSITTIS house brand — will find a particularly convincing solution here.
