What effect will the impurities of quartz sand have on the whiteness of quartz sand
The original color of quartz sand is white, but it will be polluted to different degrees under the action of the natural environment over the years, showing black, yellow, or red and other associated or symbiotic mineral impurities, so it affects the whiteness and quality of quartz sand.
① Yellow impurity
It’s basically an oxide of iron, attached to the surface or inside of the quartz sand. Some of the yellow impurities will be clay or wind fossils.
② Black impurity
It is a product of magnetite, mica, tourmaline minerals or mechanical iron.
③ Red impurities
Hematite is the main mineral form of iron oxide, the chemical composition is Fe2O3, crystal belongs to tripartite crystal system oxide minerals. In red sandstone, hematite is a cementation of quartz grains that gives the rock its color.