For example, laser spot sizes of 100 microns or less allow a user to extract multiple argon samples from across a small mica or feldspar grain.
The results from a laser probe can be plotted in several graphical ways, including a map of a grain showing lateral argon distribution.
This imprecision (and inaccuracy) is transferred to the secondary minerals used daily by the Ar age equation will become continually more refined allowing much more accurate and precise ages to be determined.
Because the J value is extrapolated from a standard to an unknown, the accuracy and precision on that J value is critical.
The quantity of potassium in a rock or mineral is variable proportional to the amount of silica present.