Ornamental stone grades and standards from Brazil

The short answer

Granite and quartzite are not graded under a single Brazilian government standard the way sugar or cotton are. What governs a purchase is a combination of US and European material specifications, the mining title behind the quarry, and, for quartzite specifically, a real and documented risk that what is offered as quartzite is actually a different, softer stone.

US standards: ASTM

ASTM publishes the two specifications most often referenced for Brazilian granite and quartzite sold into the US and other markets that use ASTM references:

• ASTM C615/C615M-23, "Standard Specification for Granite Dimension Stone," dated 15 December 2023. This is the reference standard for granite as a dimension-stone material. Its specific numeric requirements were not extracted while preparing this page; only the standard's number, title and date were confirmed.
• ASTM C616/C616M-22, "Standard Specification for Quartz-Based Dimension Stone." This standard classifies quartz-based stone into three classes: Class I, sandstone; Class II, quartzitic sandstone; and Class III, quartzite proper. It sets requirements for absorption by weight, density, compressive strength, modulus of rupture and abrasion resistance, which is the technical basis for distinguishing a true Class III quartzite from a lower class of quartz-based stone, separate from the marble-mislabelling question below.

EU standard: EN 1469

For buyers in the European Union, EN 1469:2015, "Natural stone products - Slabs for cladding - Requirements," is the harmonised product standard behind CE marking for stone cladding slabs. A slab intended for facade or cladding use in the EU needs to meet this standard and carry the corresponding CE mark; the detailed requirements were not extracted from the standard's own text in this pass.

A Brazilian standard specific to granite for cladding, ABNT NBR 15844, was referenced in research for this page but could not be verified directly; treat it as a standard to ask a supplier about rather than one confirmed here.

The quartzite mislabelling risk

This is the standard-adjacent risk that matters most in practice. Natural Stone Institute campaign material, published 20 February 2020, is direct about it: "There is really no such thing as soft quartzite, and in most cases that term means the stone is marble." True quartzite (ASTM C616 Class III) is a hard, silica-based metamorphic stone. Marble and dolomite are calcium- and magnesium-carbonate stones, much softer and far more reactive to acid, and a slab of either can be marketed using "quartzite" language that a buyer without a lab has no easy way to check from a photo or a spec sheet alone.

The two field tests recommended by that source, a glass-scratch test (true quartzite scratches glass; marble and dolomite generally do not) and an acid-etch test (a drop of vinegar or lemon juice etches or fizzes on marble and dolomite; true quartzite shows no such reaction), are set out with more detail on how to verify a Brazilian ornamental stone exporter. Running them on a sample slab before accepting a full lot is a low-cost check against the specific risk this category carries.

Where this fits

The company and quarry-level checks, and the two mislabelling tests in full, are on how to verify a Brazilian ornamental stone exporter. Trade figures are on Brazilian ornamental stone export data. Confirming a specific slab lot against the contract before it ships is the job of pre-shipment inspection.

Sources

• ASTM C615/C615M-23, granite dimension stone: store.astm.org, primary, title and date confirmed, full requirements not opened.
• ASTM C616/C616M-22, quartz-based dimension stone, classes and test parameters: store.astm.org, primary.
• EN 1469:2015, EU natural stone cladding slabs: standards catalogue reference, secondary, full text not opened.
• ABNT NBR 15844 (granite for cladding): referenced but not verified in this pass.
• Marble and dolomite sold as "soft quartzite," and the glass-scratch and acid-etch tests: Natural Stone Institute, "How to Be Your Own Stone Sleuth," 20 February 2020, usenaturalstone.org. Secondary, industry body.

Facts checked 24 September 2026. Confirm the current text of any cited standard directly with ASTM, CEN or ABNT before writing a numeric requirement into a contract.