One hundred microlitres of saline was mixed with the contents of each well and then each well scored for opalescence.
Such an effect parallels critical opalescence in classical fluids at near-critical conditions.
Well-known examples are the light scattered from the sky (which is ultimately responsible for its color) or the opalescence of light in a fluid at the critical point.
Contrarily, "opalescence" is correctly applied to the milky, turbid appearance of common or "potch" opal.
This variety exhibits pleasing chatoyancy or opalescence that reminds one of an eye of a cat.
