Quartz Sand Used in Water Filter

Appearance
High quality quartz sand has a light grey or off-white color and feels very smooth, with no visible impurities. Inferior grades may appear darker, dirtier or contain clay/rock particles.

Silica Content
A laboratory chemical analysis can precisely determine silica (SiO2) levels. Top quartz sand exhibits 95% or greater silica, while low grades contain impurities lowering this.

Particle Shape
Under a magnifying glass or microscope, superior quartz particles will have angular, irregular shapes for strong interlocking. Rounded grains symbolize weathering or inadequate processing.

Surface Texture
High grade quartz will show a very smooth, polished texture from proper abrasion and washing. An unusually coarse, pitted or flaky surface hints at poor purification.

Hardness Test
Scratch quartz grains using a steel needle or streak plate. Superior quartz remains unscratched while low grades may be marred, indicating softer mineral inclusions.

Bulk Density
Weighing a known volume, heavy quartz sand of around 2.65 g/cm3 ensures high silica content and no voids. Lighter readings mean impurities or damage lowering density.

Filtration Performance
Ultimately, in a laboratory filtration test, premium quartz will clarify water faster with lower turbidity versus questionable grades containing soluble impurities.

By astutely examining these physical and chemical properties, experienced operators can easily differentiate between top-notch quartz suitable for treatment and inferior substitutes during procurement.