Marble vs Onyx: hardness, care and where to use each

Marble and Onyx compared: typical hardness, water absorption and strength of each stone family, usual finishes and suitability use by use, with the stones of each family in our catalogue.

By Fabrizio Musetti, Marmi di Carrara srl, quarry owners in Carrara since 1956. Updated: 8 October 2026

Marble vs Onyx

	Marble	Onyx
Mohs hardness	3–4	3–4
Water absorption (EN 13755)	0.1–0.6 %	0.1–0.5 %
Bulk density (EN 1936)	2,650–2,750 kg/m³	2,650–2,750 kg/m³
Compressive strength (EN 1926)	70–140 MPa	60–110 MPa
Flexural strength (EN 12372)	7–20 MPa	6–15 MPa
Weight of a 2 cm slab	about 54 kg/m²	about 54 kg/m²
Typical finishes	Polished, honed, brushed, sandblasted, bush-hammered	Polished, honed; often back-lit
Typical uses	Flooring, wall cladding, bathrooms, vanity and kitchen tops, stairs, fireplaces, sculpture	Feature walls, back-lit panels, bar counters, vanity tops, luxury interiors
Interior floors	Excellent	With care
Wall cladding	Excellent	Excellent
Kitchen worktops	With care	With care
Bathrooms and wet areas	Excellent	Good
Exterior paving and façades	Good	Not recommended
Frost exposure	With care	Not recommended
Back-lighting	Limited	Excellent
Stones in our catalogue	691	38

Density, absorption and strength are indicative ranges for the stone family, not test results of this block. Certified values for a specific lot are provided with the offer.