A professional stone quote should allow the technical team to evaluate more than colour and price. Test reports are useful only when the test method, sample identification and intended application are clear.
Common performance indicators
Water absorption and bulk specific gravity: ASTM C97 is one referenced test method for dimension stone. Absorption can be relevant to staining, exposure and long-term detailing, although one number never determines suitability by itself.
Flexural strength: A test such as ASTM C880 can help the project engineer evaluate stone panels under bending loads. It does not replace a full cladding design or anchorage calculation.
Modulus of rupture: ASTM C99 is another listed stone test method. The project specification should say which test and value are required rather than assuming all stones need the same threshold.
Abrasion and surface performance: For heavy traffic floors or outdoor paving, appropriate wear and slip testing may be necessary, alongside attention to the installed finish.
Avoid misleading comparisons
- Confirm the report refers to the specific stone variety being offered.
- Record sample source, dimensions, laboratory and date.
- Compare values obtained using the same test standards and units.
- Ask whether filling, resin treatment or surface finishing affects the applicable result.
- Verify project-specific local code and acceptance criteria with the design team.
A simple request to send
Please provide the stone identification, current representative samples, available absorption and strength reports, test standard references, manufacturing tolerances and any known limitations for the intended application.
Avoid making a universal pass/fail judgment based on a single metric. The correct decision is a combination of engineering, aesthetics, installation and service conditions.