Silicon does not occur freely in nature, but rather as Silica (SiO₂) in crystalline forms and combines with other oxides and metals to form a variety of useful silicates, such as alumina silicates found in clay and clay borne products.

Silicates are the most abundant minerals of the Earth's mantle and crust. Silica is the major constituent of sand beds on coastal areas and is a significant constituent in most soils.

Silica is hard, resistant to corrosion and is only slightly soluble in water. The solubility of Silica in water depends on the pH of the water and the mineral bed in contact with the water.

In industry, heating plants and reverse osmosis processes need to accurately monitor Silica concentrations in water because of scale formation.

• Method: Checker Disc
• Range: 0-40 mg/L; 0-800 mg/L
• Smallest Increment: 1 mg/L; 40 mg/L
• Chemical Method: Colorimetric
• Number of Tests: 100
• Weight:  712.5 g