Supersaturated solution
= Supersaturated solution
A <supersaturated solution> has an <ion product> above the relevant <solubility product>. It can persist through <metastability>: <nucleation> must first create a sufficiently large new <solid> region. Added surfaces, impurities and mixing history can affect that barrier. Therefore a clear sample during a finite observation does not prove undersaturation, and visible cloudiness does not measure the <ion product>.