Clay has long been proposed as a substrate for life’s origins. Clay particles swell and shrink with wetting and drying, which provides an unstable environment for the origin of life. Micaceous clay has flecks of mica in it that do not swell and shrink with wetting and drying, because the mica sheets are held together by potassium ions K + , which are larger than the sodium ions Na + that hold other clay sheets together. K + is present at high concentrations in cells of living systems, but most research on the origins of life involves sites that have higher concentrations of Na + than K + . For this reason, mica is a substrate for life's origins that merits further study. Interesting biophysics is involved in the possible origin of life between mica sheets in micaceous clay. For example, an energy source at the origins of life is the mechanical energy of mica sheets, moving open and shut in response to fluid flow or heat changes, before chemical energy such as ATP was available.
Helen G. Hansma (Sun,) studied this question.