Reading a stone spec: the ASTM tests that actually matter
Absorption, flexural strength, abrasion — which ASTM numbers to ask for by stone type, and what they tell you about where a stone can go.
Every stone type has its own standard
Granite is specified to ASTM C615, limestone to C568, marble to C503, quartzite to C616 and travertine to C1527. Each sets minimum physical values for that stone family — so 'it passes ASTM' is meaningless without naming the standard.
The four numbers worth asking for
Absorption (C97) predicts staining and frost risk — low is better outdoors. Flexural strength (C880) and modulus of rupture (C99) tell you whether a thin panel will hold. Abrasion resistance (C1353/C241) tells you whether a floor will wear. For exterior, also ask about freeze-thaw (C1528).
Type-level vs lot-level
Density and family behaviour are type-level facts you can publish. Absorption and flexural values vary by lot and quarry block, so a credible source gives type-level guidance now and confirms per-lot lab values at quotation — never invented numbers.
Match the test to the use
A worktop cares about absorption and acid sensitivity; a ventilated facade cares about flexural strength and anchorage; a floor cares about abrasion and slip. Ask for the numbers your application actually depends on, not a generic 'datasheet'.