Silicon in natural bodies of water mainly come from the hydrolysis of silicate and silicate minerals. When the amount of H4SiO4 released from weathering is high, SiO2 would be deposited. Crystalline and amorphous SiO2 are soluble and temperature changes its solubility. For example, the concentration is 6.0mg/L at 25℃ while 26 mg/L at 84℃. In natural water, SiO2 content is higher than that of quartz but is lower than amorphous SiO2. In most conditions, the concentration falls between 1 mg/L to 30 mg/L. In a few areas, the concentration can reach 100 mg/L. In some extreme conditions such as an intermittently hot spring, the SiO2 concentration could be as high as 762 mg/L to 804mg/L. In surface seawater, the concentration is lower than 1mg/L. SiO2 concentration is also low in lakes due to absorption by organisms. Generally speaking, silicon accumulates in seashells and bones.