Industrial buyers know the gap between untreated silica and washed, processed, high-purity quartz. It shows up in whiteness, melt behaviour, filter life and how well a furnace lining holds up. This guide explains how quartz is graded and which grade belongs in which process.
Processed quartz vs raw silica
Raw beach or river sand is a mix of quartz, feldspar, clay, iron minerals and organic matter. Processed quartz sand is that material washed, sized and purified until it becomes a consistent industrial raw material. The benefits are concrete:
- High purity — SiO₂ of 98–99.9% with low iron for clean melt and whiteness.
- Uniform shape and size — better packing, higher density, stronger bonds.
- Ultra-low clay and dust — cleaner finishes and longer filter life.
- High refractoriness — coarse grades withstand 1600 °C+ furnace temperatures.
- Batch consistency — verified by laboratory analysis on every lot.
How quartz sand is graded
Four attributes define a grade, and a good specification pins down all four:
- Chemical purity — SiO₂ content and the impurity profile (Fe₂O₃, Al₂O₃, TiO₂).
- Grain size / mesh — from fine filter media to coarse foundry grades, expressed as mm or mesh.
- Grain shape — angular grains bond well in ceramics and refractories; rounded grains flow and pack differently.
- Brightness / whiteness — important wherever the final product's colour matters.
Grade by grade
| Grade | Key spec | Character | Best for |
|---|---|---|---|
| Premium (SKU01) | SiO₂ 99.9%, Fe₂O₃ <100 ppm, brightness >96% | Crystal white | Premium & optical glass, solar |
| QBR (SKU02) | SiO₂ ≥98%, angular | Snow white | Sanitaryware & ceramic tiles |
| Coarse (SKU03) | 1.00–3.00 mm, up to 1600 °C+ | Angular, uniform | Foundry & furnace linings |
| G.C (SKU04) | 0.40–0.80 mm, SiO₂ 98%+ | Clean, sub-angular | Pressure filters & water treatment |
Applications in depth
Glass & solar
Premium float, container, optical and solar glass demand the highest purity and lowest iron — even a trace of Fe₂O₃ adds a green tint. See our guides to glass sand specifications and low-iron quartz for solar.
Sanitaryware & ceramic tiles
Angular, snow-white quartz gives sanitaryware and tiles their whiteness, mechanical strength and low water absorption. Consistent grain size keeps the ceramic body uniform.
Foundry & refractories
Coarse, high-refractoriness quartz lines induction furnaces and ladles and forms moulds that must withstand molten-metal temperatures without breaking down.
Water treatment & filtration
Graded, low-dust quartz is the workhorse filter media in pressure sand filters, RO pre-treatment and WTP/STP plants — chemically inert, mechanically strong and safe for potable water. Uniform grading is critical for even flow and backwash.
Sandblasting & construction
Hard, angular quartz is used as a blasting abrasive and as a filler and aggregate in construction chemicals, tile adhesives and epoxy floors.
Paint, rubber & chemicals
Fine quartz powder is a functional filler that adds hardness, durability and chemical resistance to paints, coatings, rubber and sealants.
Matching grade to application
The rule is simple: purity and whiteness rise as the application gets more demanding, and grain size is chosen for the process. Glass and solar sit at the top of the purity ladder; sanitaryware needs whiteness and the right shape; foundry needs coarse and refractory; water treatment needs uniform, clean, mid-fine grains.
Packaging, logistics & QC
Quartz ships in 25 kg or 50 kg bags, 1–1.5 tonne jumbo/FIBC bags, or in bulk, by container or bulk vessel. Every consignment should carry a Certificate of Analysis, with third-party SGS/Intertek inspection available on request. Custom mesh sizes are graded to the buyer's specification.
What to specify when ordering
To get the right grade first time, tell your supplier the application, the SiO₂ and iron targets, the grain size / mesh, the brightness if colour matters, the packaging, and the destination port and volume. A precise brief gets a firm, comparable quote.
Ambizent supplies all four grades — see our Quartz Sand range — sourced in India and traded from the UAE, with a COA on every shipment.
Frequently asked questions
What is the difference between quartz sand and ordinary sand?
Which quartz grade is used for glass?
What quartz sand is used in water treatment?
What makes quartz suitable for foundry use?
How is quartz sand packed and shipped?
Ambizent International Trading supplies sulphur, PVC & plasticizers, polyurethane chemicals and premium quartz sand to manufacturers in 30+ countries, with a Certificate of Analysis on every shipment. Request a quote →