Granite Samples and Mockups: Approval Process for Importers

A reliable granite samples approval process converts the intended appearance into a controlled production reference. Before an importer authorizes manufacturing, the approved package should identify the stone, show its permitted visual range, reproduce the specified finish and fabrication details, and state what the sample does not approve. For variable or technically demanding work, a small chip alone is insufficient: use range samples, finish samples and, where appropriate, a full-size mockup supported by written specifications and relevant test evidence.

What granite sample approval should accomplish

Natural dimension stone is selected not only by name but also by size, shape, color, grain, pattern, finish, durability and strength. The U.S. Geological Survey identifies these as normal dimension-stone selection considerations, which explains why approval cannot be reduced to matching a single photograph or catalog label. USGS dimension stone guidance provides the broader material context.

The approval record should answer four questions:

• Identity: What material is being offered, and how is it linked to the proposed production supply?
• Appearance: What color, grain, movement, inclusions and natural variation are acceptable?
• Fabrication: What finish, dimensions, edges, joints, cutouts or anchoring details must production reproduce?
• Verification: Which characteristics will be checked before shipment, and which require laboratory or engineering evidence?

Approval should be conditional on continued conformity to the purchase specification. It should not waive dimensional tolerances, quantity requirements, packaging rules, test criteria or defects that are not visible in the submitted sample.

Geological identity and trade names

Commercial granite is a broad category

In geological classification, granite has a defined mineral composition and origin. In the dimension-stone trade, “granite” is a broader behavioral group that can include gabbro, anorthosite, basalt, gneiss and other hard silicate stones. The Natural Stone Institute comparison of scientific and commercial definitions explains this distinction.

This difference matters because a trade name does not prove geological identity or performance. If mineral composition, petrographic classification or suitability for a particular exposure is important, request appropriate documentation rather than inferring it from the word “granite.”

Record names without treating them as proof of origin

A sample label should state the supplier's exact commercial name and internal material code. Where origin is material to the contract, also request the documented country and quarry or deposit identification, but do not accept an unsupported place name as evidence. China-based sellers may offer both domestically quarried and imported stones. Marketplace listings illustrate the wide mixture of commercial names, finishes and stated origins available through Chinese suppliers, but listings do not independently verify any supplier or quarry claim. See the StoneContact China granite listing for market context.

Each approved piece should carry a durable reference number tied to the quotation, specification revision, sample date and proposed production source. If the source changes, the buyer should require resubmission rather than assuming that an identically named stone will match.

Sample types and approval sequence

Do not ask one sample to perform every function

Different samples control different risks. A disciplined sequence moves from identity and broad selection toward production-scale verification:

1. Initial selection sample: A portable piece used to compare candidate materials. It is useful for screening, not final range approval.
2. Range set: Multiple pieces selected to represent the proposed light, typical and dark appearance, together with relevant changes in grain, veining or movement. The set should show acceptable variation rather than only the most attractive portion.
3. Finish sample: A piece made in the specified polished, honed, flamed, bush-hammered, split-face or other finish. It should use the proposed stone and show the expected surface character.
4. Fabrication sample: A piece showing edge profiles, chamfers, grooves, drilled holes, kerfs, resin treatment or other workmanship that cannot be judged from a flat face.
5. Production-size mockup: One unit or an assembled area reproducing dimensions, joints, pattern, orientation and interfaces at a scale sufficient for evaluation.
6. Control sample: The signed and dated approved reference retained for comparison with production and pre-shipment inspection.

At least two equivalent control sets are advisable when practical: one held by the buyer or appointed representative and one held at the production location. If an independent inspector will use a separate set, record all three under the same approval reference.

Practical approval schedule

Finishes and application-specific mockups

Approve the actual finish, not its written name

Finishing changes how color, grain and surface features are perceived. Polishing generally creates a reflective surface, honing produces a lower-sheen appearance, and textured processes such as flaming or bush hammering create a visibly different profile. An overview of common finish categories is available in the Marble.com granite finishes reference.

Finish terminology alone is not an adequate standard because texture and sheen can vary with equipment, abrasives, process sequence and stone response. The approval piece should therefore be produced using the intended finish route whenever possible. Review it clean and dry under agreed lighting. If the installed work will commonly appear wet, an additional wet observation may be recorded, but it should not replace the dry reference.

Specify whether approval concerns appearance only or also measurable properties such as gloss, surface profile or slip-related performance. Any numerical criterion must identify the measurement method and acceptance range. Buyers can review the principal finish categories under granite finishes, including polished granite, bush-hammered granite and split-face stone.

Match the mockup to the application

• Countertops: Show the selected finish, edge profile, seam arrangement, backsplash junction and representative cutout details. Review slab-to-slab movement separately when pattern continuity matters. See granite countertop applications.
• Flooring: Assemble several tiles with the intended joint width and orientation. Include contrasting pieces from the approved range rather than creating an artificially uniform panel. See granite flooring.
• Facades: Use a panel large enough to evaluate grain scale, orientation, joint relationships and visible edge treatment. Anchors, kerfs and engineering requirements remain subject to project-specific design. See granite facades.
• Stairs: Reproduce the tread finish, nosing, riser interface, exposed edges and any grooves. See granite stairs.
• Exterior paving and landscaping: Include the surface, edge finish, thickness and representative joint. Performance requirements should reflect the actual exposure and installation design.

Specifications and test evidence

Sample approval is not technical qualification

A sample can confirm visible characteristics but cannot establish structural strength, absorption, abrasion resistance, durability or fitness for an engineered assembly. ASTM C615/C615M-23 covers material characteristics, physical requirements and sampling for granite dimension stone used in general building and structural work. It identifies properties including absorption, density, compressive strength, modulus of rupture, abrasion resistance and flexural strength. Refer to the active ASTM C615/C615M specification and the project's adopted edition.

Testing should be selected by the architect, engineer or specification writer according to application and exposure. ASTM C97/C97M-25 addresses absorption and bulk specific gravity, while ASTM C880/C880M-25 addresses flexural strength using beam specimens. Test reports should identify the stone, specimen source, test method and edition, laboratory, test date, conditioning and orientation where applicable. A report for a similarly named material should not automatically be treated as evidence for the proposed production source.

Define contractual acceptance separately

The purchase specification should state dimensions, tolerances, finish, allowable repairs, edge details, visual range, marking, quantity, packaging and inspection plan. Do not copy generic tolerances into the order without confirming that they suit the product and installation. Requirements for granite slabs, cut-to-size facade panels, calibrated tiles and stair units are not interchangeable.

Where drawings and samples differ, the contract should establish precedence. A practical rule is that drawings control geometry, written specifications control measurable requirements, and approved samples control the agreed visual range and workmanship reference. Any project may adopt a different hierarchy, but it should be explicit before production.

Inspection, approval records and change control

Issue a traceable decision

Use clear statuses such as “approved,” “approved as noted,” “revise and resubmit” or “rejected.” An approval should state the sample reference, date, reviewer, approved characteristics and outstanding conditions. Avoid informal messages such as “looks good,” which do not identify what has been accepted.

The retained sample should be signed across a label or seal where practical. Photograph the front, back, edges, label and full set with a scale reference, but treat photographs as records rather than color standards. Screens, cameras and lighting can alter apparent color and contrast.

Inspect production against both sample and specification

Pre-shipment inspection should compare randomly selected production units with the approved control range under consistent viewing conditions. The inspection should also cover dimensions, finish consistency, fabrication details, visible defects, markings, quantities and packaging as required by the order. The granite quality-control guide provides a wider inspection framework.

If the proposed stone source, finish route, repair method, dimensions or fabrication details change, pause the affected work and issue a documented resubmission. Approval of one change should not be interpreted as approval of unrelated deviations.

Price factors and China sourcing context

Budget for approval as a project activity

Sample costs vary with material availability, sample size and weight, number of finishes, edge work, mockup complexity, packaging, courier service, testing and resubmission rounds. Textured finishes or one-off details may require separate setup. Large assembled mockups can also require crating rather than parcel shipment. Whether sample charges are refundable or credited against production is a commercial term that must be confirmed in writing; no universal practice should be assumed.

Control the handover from sales sample to production

When sourcing from China, establish whether the contracting party is the processor, quarry-connected seller, exporter, trading company or another intermediary. The business model does not by itself determine quality, but it affects document flow and responsibility for retaining the approved sample. See factory versus trading company and the broader China granite supplier guide.

Attach the production approval register, photographs, drawings and control-sample references to the purchase order or supply agreement. Require the production facility and any inspection party to receive the same revision. For multi-material orders, maintain separate codes and approval packages so that similar gray, black or beige stones are not confused during production or packing.

Importers should also allow time for physical sample preparation, international courier delivery, review and possible resubmission before fixing the production schedule. Consolidating samples may reduce freight, but it can delay every material if one item is unfinished. The approval plan should therefore be coordinated with the wider granite import process.

A complete approval file does not eliminate the natural variability of stone. Its purpose is to define acceptable variability, establish an auditable reference and reduce avoidable disagreement before the shipment leaves China.

Printable working records

Use these blank records to document your own order and observations: Granite Sample Approval Record. They can be filled in the browser or printed for handwritten notes.

Build your specification text

Use the specification builder to combine your entered requirements with the existing tolerance and sample approval wording from these guides. It provides copyable text and has no submission function.