Thassos A3 is an economically attractive quality grade of the world-famous Greek Thassos marble from the Panagia quarry district on the island of Thassos in northern Greece — a light white base tone with subtle grey clouding and somewhat more clearly visible vein traces than the premium grades A1-A2. The suffix A3 denotes the standard quality level of the Greek quarry classification, the same dolomitic dimension stone as the premium grades with improved acid resistance compared with calcite marbles. Frost-resistant — used for wall claddings, floor surfaces, bathrooms, staircases and interior fit-outs with a classically Greek, light appearance.
Petrographically a dolomitic marble (86 % dolomite, 12 % calcite, 2 % quartz) from the Panagia quarry district on the Greek island of Thassos. “A3” denotes the standard quality level of the Greek quarry classification — the same material as the premium grades A1-A2 with identical technical properties, but somewhat more visible natural movement and vein traces in the white base shade.
Thassos A3 is the economically attractive, mid-price quality grade of the world-famous Thassos marble from the long-established quarries in the Panagia quarry district on the Greek island of Thassos in the northern Aegean. The island of Thassos has been known for its white marble since Greek antiquity — already in classical Greek antiquity Thassos was won for sculptural and architectural purposes, and in the modern stone market Thassos has become a synonym for the “whitest marble”. The Greek quarry classification divides the Thassos marbles into the quality levels A1, A2 and A3, which all come from the same dolomitic marble — they differ only in the purity of the white colouring and the visibility of vein markings: A1 and A2 (often grouped together as A1-A2) are the premium grades with maximum white purity and minimal veining; A3 is the standard grade with somewhat more visible movement and occasional finer grey vein zones.
Geologically, Thassos A3 — like all Thassos grades — is an exceptionally calcium-magnesium-carbonate-rich crystalline metamorphic marble with a high dolomite content (typically 86 % dolomite, 12 % calcite, 2 % quartz according to DNSA mineral analysis). This mineralogical composition distinguishes the stone from purely calcitic white marbles such as Carrara: the high dolomite proportion brings two important advantages — better acid resistance compared with calcite marbles, and greater hardness. The microstructure is medium-grained crystalline and essentially isotropic. Geologically the stone formed around 30 to 50 million years ago during the Alpine orogeny in the Rhodope complex from pure Mesozoic limestone formations. The A3 grade comes from the same quarry faces as the premium grades, but represents quarry areas with somewhat more natural mineral variability.
Visually, Thassos A3 is marked by a light white appearance, though not quite as pure as the premium grades A1-A2. The base shade is a luminously radiant white to cream-white ivory with a fine crystalline microstructure. Unlike the premium grades, A3 shows somewhat more visible movement — fine clouding, occasional grey vein zones and subtle tonal nuances that lend the surface a livelier material signature. This variability makes A3 a more characterful, less sterile choice than the almost completely homogeneous A1-A2 — many architects and designers value the A3 grade precisely because of this visible natural liveliness. The finishes available from stock are listed in the »Finishes« block further down.
Technically, Thassos A3 shows values identical to those of the premium grades — the A1/A2/A3 classification concerns the visual quality exclusively, not the mechanical properties. Bulk density 2,850 kg/m³ (exceptionally high), compressive strength 99.7 MPa, flexural strength 13.3 MPa, abrasion resistance 6.60 cm³/50 cm² and water absorption 0.23 %. Frost resistance is DNSA-documented. Like all carbonate marbles, Thassos is acid-sensitive, though thanks to the high dolomite proportion it is somewhat more robust against concentrated acids than pure calcite marbles. Polished surfaces are not stable in the long term in openly weathered external situations; structurally protected applications or more matt surface finishes are to be preferred there.
In interior fit-out, Thassos A3 is an economically attractive choice for design demands that call for a classically Greek, light marble appearance without having to pay the premium price of the A1-A2 grades. Classic applications are wall claddings in hotel lobbies and reception areas, bathrooms and spa facilities, vanity tops, bar counters, feature walls in prestige residential and commercial spaces, floor surfaces in entrance halls and living rooms, and table and console tops. The luminously white tonality with its subtle natural liveliness harmonises with every classical and contemporary design concept — from puristic modern architecture with black steel and glass to classically elegant rooms with dark timber and brass. Outdoors, Thassos A3 finds use as façade cladding, for plinth details and for entrance areas protected beneath a canopy. The A3 grade is the right choice where the material is needed in larger areas and the somewhat more variable slab character is accepted as added design value.
In stock
Current availability from our warehouse.
50 slabs in stock · plus 22 blocks
Thicknesses: 2 & 3 cm · Finishes: Polished · Available as: Slabs
Guide values for the stone type, taken from manufacturer and test reports. Natural stone is a natural product — individual batches and slabs can differ. For critical applications, request slab-specific test data.
Rohdichte
2.850 kg/m³
Druckfestigkeit
99,7 MPa
Biegezugfestigkeit
13,3 MPa
Wasseraufnahme
0,23 %
Frostbeständig
Ja
Säurebeständig
Nein
Finishes
Thassos A3 is available in a range of finishes. The finish affects appearance, feel and the care it needs.
Polished
Polishing is the most classic finish for marble and limestone — a glossy surface with the highest possible colour intensity and a pronounced depth to the veining. Depending on the mineral composition, the effect can be matte-gloss in places. Acid-sensitive — wine, lemon and vinegar leave etch marks after prolonged contact.
Care & fabrication
As a dolomitic marble, Thassos A3 is acid-sensitive, though thanks to the high dolomite proportion (86 %) it is markedly more robust against concentrated acids than pure calcite marbles such as Carrara. Indoors, use only warm water with a pH-neutral stone cleaning product for daily cleaning — acidic household cleaners, vinegar, citric acid descalers or other concentrated acidic substances can cause matt etched patches if left to act for longer. Take up spilt acidic liquids promptly with clear water — thanks to the dolomite mineralogy there is more reaction time available here than with pure calcite marbles. A professional sealer after laying, and then every 2 to 3 years, is recommended indoors in order to reduce the take-up of pigments (red wine, coffee, olive oil) — on the white tonality, pigment stains are particularly clearly visible. In the bathroom, water droplets should be squeegeed off after showering in order to avoid water droplet rings. For wall claddings, regular dusting and occasional wiping with a damp cloth is sufficient. Outdoors, the avoidance of de-icing salt in winter must be observed — chloride-free de-icing agents are the gentler alternative.
Frequently asked questions
What distinguishes Thassos A3 from Thassos A1-A2?
All three grades — A1, A2 and A3 — come from the same quarries on the island of Thassos and are technically identical (same water absorption, compressive strength, frost resistance). They differ exclusively in visual quality: A1 and A2 (often grouped together as A1-A2) are the premium grades with maximum white purity and minimal vein markings; A3 is the standard grade with somewhat more visible movement — fine clouding, occasional grey vein zones and subtle tonal nuances. A3 is more attractive in price and is chosen for applications in which the somewhat livelier material signature is valued in design terms or the budget is limited.
Is Thassos A3 poorer in quality?
No — the A1/A2/A3 quarry classification concerns exclusively the visual purity of the white tonality, not the technical quality. All three grades have identical mechanical and chemical properties: the same compressive strength (99.7 MPa), the same water absorption (0.23 %), the same frost resistance, the same dolomitic mineralogy. The A3 grade is therefore not “inferior” — it merely shows somewhat more natural movement and variability, which many architects and designers see as added design value.
What does the dolomitic mineralogy mean for care?
Thassos is a dolomitic marble with an 86 % dolomite content — which distinguishes it from purely calcitic white marbles such as Carrara. The high dolomite proportion brings two advantages in terms of care: better acid resistance (Thassos reacts more slowly and more weakly to acidic substances than pure calcite marbles, but is not completely acid-proof) and greater hardness than calcitic marbles. This improved robustness makes Thassos easier to care for than most other white marbles.
Is Thassos A3 suitable for bathrooms?
Outstandingly so. The luminously white tonality with its subtle natural liveliness creates a light, friendly atmosphere and reflects light exceptionally well — the ideal property for luxurious bathrooms and spa facilities. The low water absorption of 0.23 % and the improved acid resistance compared with pure calcite marbles are further advantages. Water droplets should be squeegeed off after showering, and acidic cleaning products must be avoided — pH-neutral stone cleaning products are standard.
Is Thassos A3 suitable for external applications?
With reservations. The low water absorption of 0.23 % and the DNSA-documented frost resistance qualify Thassos for moderately weathered external applications such as façade claddings, plinth details and entrance areas protected beneath a canopy. Polished surfaces are, however, not stable in the long term in openly weathered external situations — a matt, textured surface finish is to be preferred there. For openly weathered horizontal paving with pronounced freeze-thaw cycles and acidic precipitation, denser, acid-insensitive hard rocks are the more robust alternative.
Which slab formats are usual for Thassos A3?
Standard large formats from the Thassos quarries typically lie between 280 × 160 cm and 320 × 200 cm in thicknesses of 2 cm and 3 cm. Thinner formats (1 cm and 1.5 cm for lightweight wall claddings, 4 cm and above for stairs) as well as skirtings and tile formats for floor surfaces can also be sourced through ROSSITTIS. Because of the higher material availability of the A3 grade compared with the premium A1-A2 classes, the delivery time is often shorter and the pricing more attractive.
What does Thassos A3 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.
