The potential flaws in relative dating in archaeology are obvious.
Simply assuming that an artefact is older because it was found at a lower depth in the record is only subjective science.
As experience has been gained, the need to carefully characterize the phase being analysed, increased measurement sensitivity and increasingly sophisticated methods of sample preparation have resulted in clay mineral dates that can be related to a diagenetic age with more confidence.
Crystalline minerals when subjected to intense heat will burn with differing colours of flame.
The associated advantage of being more suitable for extremely small samples, on the order of tens of micrograms that can be readily screened for contaminants, is an attractive feature for potential application to sandstones.
When museums and collectors purchase archaeological items for their collections they enter an expensive and potentially deceptive commercial fine arts arena.
Additionally, much has been learnt of the processes of clay-mineral diagenesis.
Ar method for dating clay-mineral diagenesis in fine-grained sediments.