What calcite sand is in an engineered-stone mix, how the 10, 20 and 40-80 mesh grades differ, and what to specify in an enquiry.
Engineered stone is a blend, not a single mineral. Whether the product is cast marble, onyx, quartz-look slab, acrylic solid surface or terrazzo, the decorative face is a mix of binder — polyester or acrylic resin, or cement — and graded mineral aggregate. The coarse fraction that gives the slab its body, weight and depth usually comes from calcite. Buyers who search for calcite sand for artificial stone are trying to settle one practical question: which grain size, and how do I write it into the specification so the slab that arrives matches the sample that was approved.
This guide explains what calcite sand is in an engineered-stone mix, how the three grain grades differ, and what to put in an enquiry so the answer comes back usable.
What calcite sand is in an artificial stone mix
Calcite sand is coarse, granular calcium carbonate — the same mineral family as ground calcium carbonate powder, but held at a much larger particle size. Where GCC powder is milled down to hundreds or thousands of mesh for filling and reinforcement, calcite sand is screened and kept as discrete grains, typically from about 10 mesh down to around 80 mesh. Those grains act as aggregate: they give the cast material its mass, its colour body and, depending on size, its visible surface texture.
The words matter. “Sand” here describes the grain size and handling behaviour, not the mineral. Calcite sand is a calcium carbonate product, identified as such on the COA and the grade page — not silica sand, and not a by-product.
The three calcite sand grades we supply
TDHX produces calcite sand in three standard gradings. Each is a separate product with its own grain distribution, and each suits a different part of an engineered-stone formula.
10 mesh — the coarse structural grade
10 mesh calcite sand is the coarsest standard grade. The grains are large and uniform, with very little fine powder, which makes them a structural filler rather than a decorative one. In artificial stone they build mass and reduce binder demand; the same grade is widely used in concrete, mortar and terrazzo base work. If a slab needs weight and volume without a visible speckle, the coarse grade carries most of that load.
20 mesh — the all-round mid grade
20 mesh calcite sand sits between the coarse and fine grades. It is fine enough to read as a decorative grain in the surface and coarse enough to stay hard and stable in the binder. Many artificial-stone and cultural-stone formulas use it as the main aggregate, then adjust with a finer grade to tune the finish. It also bonds well with resin, cement and polymer binders, which is why it is the grade most often requested for engineered-stone trials.
40–80 mesh — the fine decorative grade
40–80 mesh calcite sand is the fine decorative grading. Grains are small and tightly graded, with low fine content, so the finished surface reads smooth and close rather than speckled. It is used for high-grade terrazzo, fine artificial stone, epoxy flooring fill and decorative coating aggregate — anywhere the surface has to show uniform colour with only a subtle grain.
How grain size changes the finished surface
Grain size is the single biggest lever on how an engineered-stone surface looks and behaves. Working from coarse to fine:
- Coarser grains raise bulk density and filler load, add visible speckle and give a more open, stone-like surface.
- Finer grains close the surface, raise perceived whiteness and smoothness, and improve how uniformly the slab takes a polish.
- Blended gradings let a producer stack grades — for example a coarse base with a fine top — to control structure and appearance at once.
The practical rule is that a single-grade enquiry limits you to one surface look. If the target surface still has to be developed, say so in the enquiry and ask for a grading recommendation rather than a single-grade price.
What to put in a calcite sand enquiry
A usable quotation depends on the details you supply up front. At minimum, include:
- Grain grade or target grain size — 10, 20 or 40–80 mesh, or the size window you need.
- Application — cast marble, solid surface, terrazzo, epoxy flooring, coating filler — this drives the grade recommendation.
- CaCO₃ content and whiteness target — both are adjustable at production; the windows we work to are printed on each grade page.
- Binder system — resin, cement or polymer — because compatibility and dosage differ.
- Quantity, packaging and destination port — these set the loading plan and the shipping basis.
- Test and documentation needs — COA, sieve analysis, or a pre-shipment sample.
The figures on this site’s grade pages are production targets, not a fixed certificate. CaCO₃ content, whiteness, moisture and grain distribution are confirmed batch by batch, and the batch figures are what the COA states. Where a figure is not published, ask for it rather than assuming a typical value — the grade selection guide sets out the same principle for powders and aggregates alike.
Verifying grain size before you commit
Grain size distribution is measured by sieving. ASTM C136/C136M sets out the standard test method for sieve analysis of fine and coarse aggregates, and the same principle applies to calcite sand; ISO 3310-1 governs the test sieves used to run it. A supplier who can send a sieve analysis alongside the COA is giving you something you can check, rather than a description you have to trust.
The mesh size guide explains how mesh ratings relate to actual opening sizes, which is worth reading before you convert a millimetre window into a mesh figure. For a first order, request a physical sample of the exact grade and compare its grain against the surface you want to produce.
Packing, loading and shipment
Calcite sand ships like other bulk mineral aggregate: 25 kg and 50 kg woven bags for distribution, and one-tonne jumbo bags or bulk cargo for factory projects. Because the grades differ only by grain size, correct labelling and separation matter — bags should carry the grade so that 10 mesh does not end up tipped into a 40–80 mesh bin.
For a factory buying by the container, confirm the loading plan and bag type against your shipping schedule, and confirm a free-flowing, no-fine-clumping product on the pre-shipment sample. Lead time and pricing follow the grade, whiteness and quantity you specify — the same factors set out in the note on what drives calcium carbonate pricing.
Choosing a calcite sand supplier for artificial stone
Engineered-stone producers change formulas slowly and repeat them for years, so the supplier decision is really a consistency decision. Look for a producer who can hold a grain grade from batch to batch, who grades by sieve analysis rather than by eye, and who will put the batch figures on a COA you can verify against your incoming inspection. TDHX is based in Haicheng, Liaoning, and produces calcite sand alongside its ground calcium carbonate line, so a single supplier can cover the coarse aggregate and the fine filler in the same formula. The mineral is also used in construction and decorative work well beyond engineered stone, so the grade should follow the application, not the other way round.
To move a project forward, send the grain grade, application, target CaCO₃ and whiteness, quantity and destination port, and ask for a sample of the exact grade.
