Product Overview
Thassos White 18" x 18" Polished Marble Tile is an authentic natural stone quarried exclusively on the island of Thassos, Greece. Recognized globally as the benchmark for pure white natural stone, Thassos marble features a brilliant crystalline structure that reflects and refracts light with minimal background veining.
Unlike Italian marbles like Carrara or Calacatta that feature prominent gray or gold veining, Thassos delivers a clean, uniform, snow-like field. The mid-to-large 18" x 18" square format offers a balanced architectural scale that expands visual space while drastically reducing grout lines across primary bathroom floors, open living spaces, luxury shower surrounds, and kitchen backsplashes.
Technical Specifications
| Technical Property |
Value / Specification |
Standard / Compliance |
| Material Type |
Authentic Natural Greek Marble (Calcite) |
100% Natural Stone |
| Origin |
Thassos Island, Greece |
Premium Select Grade |
| Nominal Dimensions |
18" x 18" (45.7 cm x 45.7 cm) |
Rectified / Straight Cut |
| Thickness |
3/8" (~10 mm Calibrated) |
Standard Residential/Commercial Profile |
| Surface Finish |
High-Gloss Polished |
Mirror-Like Reflective Finish |
| Weight per Sq. Ft. |
Approx. 5.50 lbs / sq. ft. |
Heavy Natural Stone |
| Shade / Tone Variation |
V1–V2 (Uniform to Slight Variation) |
Natural Crystalline Field |
| Water Absorption |
Low to Moderate (< 0.5%) |
ASTM C97 |
| Flexural Strength |
High Density / Structural Stability |
ASTM C880 |
| Applications |
Interior Floors, Feature Walls, Shower Surrounds, Backsplashes, Fireplaces |
Interior Dry & Wet Areas |
Recommended Applications
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Primary Suite Floors & Wet Rooms: Main bathroom floors, floor-to-ceiling shower surrounds, and vanity feature walls.
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Open Living Spaces & Foyers: Entryway floors, dining room floor fields, and architectural fireplace surrounds.
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Commercial Interiors: Boutique hotel bath suites, luxury retail floors, and executive powder rooms.
Installation & Handling Guidelines
⚠️ CRITICAL WARNING: TRANSLUCENT MARBLE MORTAR & SEALING PROTOCOL
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Pure White Thinset Mortar Only: Thassos is a highly crystalline, translucent marble. Never use gray thinset mortar, as it will show through the stone and permanently discolor the installation. Always set using an ANSI A118.4 / ANSI A118.15-compliant pure white polymer-modified thinset (such as MAPEI® Ultraflex 2 White or LATICRETE® 254 Platinum White).
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100% Mortar Coverage (Flat-Trowel Technique): Back-butter every tile and flat-trowel the mortar bed to eliminate trowel ridges. Ridges will shadow through the translucent stone under direct light.
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Sealing Strategy: Apply a premium solvent-based impregnating penetrating sealer (such as Miracle Sealants 511 Impregnator or StoneTech® BulletProof®) prior to grouting and again after full grout cure to protect the crystalline matrix from moisture and pigment absorption.
Professional Recommendations
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Grout Selection: Pair with an unsanded grout in "Bright White" or "Avalanche" to achieve a seamless, continuous stone field.
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Lippage Prevention: Use a mechanical tile leveling system during installation to maintain flat, even transitions across 18-inch tile edges.
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Substrate Flatness: Ensure floor substrates are flat within 1/8" over 10 feet prior to installing 18x18 tiles.
Care & Maintenance
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Routine Cleaning: Clean exclusively with pH-neutral stone cleaners (e.g., StoneTech® Revitalizer). Never use acidic cleaners, vinegar, bleach, or abrasive pads on marble.
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Spill Protection: Wipe up acidic liquids (wine, juice, vinegar, hair dye) immediately to prevent surface etching on the polished finish.
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Resealing Schedule: Reapply an impregnating penetrating sealer every 12 to 18 months in high-use wet or floor areas.
Design Profile
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Aesthetic Inspiration: Ultra-Luxe Minimalist, Modern Grecian, High-Definition Contemporary, and Monochromatic Sanctuaries.
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Layout Ideas: Straight grid layout for symmetrical balance, diagonal diamond pattern for classic architectural depth, or 1/2 offset brick bond.
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Complementary Accents: High-gloss white cabinetry, polished nickel or champagne bronze fixtures, and light oak millwork.
Frequently Asked Questions
Why is white thinset mortar required for Thassos White marble?
Thassos White is a naturally translucent crystalline marble. If gray mortar is used, the dark pigment will shadow through the stone body, causing the brilliant white tile to appear muddy or gray. Always use a premium pure white thinset mortar.
Is 18" x 18" polished Thassos marble safe for shower floors?
While 18" x 18" tile works exceptionally well on shower walls and dry bathroom floors, polished 18x18 tile can become slippery on shower pan floors when wet. For shower pans, smaller formats with frequent grout lines (such as a 2" hexagon or 1" x 1" mosaic) are recommended for better traction and slope-to-drain flexibility.
How does Thassos White compare to Carrara or Calacatta marble?
Carrara and Calacatta marbles feature prominent gray, charcoal, or gold veining. Thassos White is prized for being the purest, whitest natural marble in the world, featuring a uniform snow-like background with a light-refracting crystalline structure and virtually no veining.
Is Thassos White tile suitable for outdoor use?
No. Natural calcite marble is sensitive to pool chemicals, acidic rain, and freeze-thaw moisture expansion. Thassos White is engineered strictly for interior dry and wet wall/floor applications.
