@Shivaran
you're right, it's not carbon 14, but it's not imposible
"The study of old metals generally focuses on the chemical nature of the metal or alloy, the technique of implementation, the identification of corrosion processes and the analysis of surface deposits.
The study of gold objects is carried out from massive samples, surface samples (replicates) and elementary chemical analysis beam extracted directly on the surface of the object ( PIXE ) or when possible by LA-ICP -MS .
Contributions
Gold is a noble material and therefore "unalterable", the study of its antiquity is complicated and is realized by an indirect observation focusing on the alteration of the elements that are allied to it.
The alteration of a gold alloy usually results in the appearance of dissolutions at the grain boundaries and a gold enrichment of the surface. These phenomena are related to the gradual departure of the less stable elements (copper, silver) present in the metal.
These phenomena can be natural or artificial. Their appearance and the presence or absence of corrosive chemicals make it possible to distinguish the different types of deterioration.
The identification of the process of manufacture of the object, the analysis of the composition of the metal or alloy and the study of non-metallic inclusions (sulphide and copper oxide, etc.) make it possible to verify the absence of technical anomalies in comparison with archaeometallurgical data.
The study of the deposits and their interaction with the corrosion products of the surface of the alloy reveal the medium of conservation of the object, or of possible surface treatments, old or recent.
Methodology
The analysis methodology differs little from that used for copper alloys or silver objects.
A stereomicroscope examination of the object is always desirable to understand its structure, its manufacturing technique and to assess its general state of deterioration. Particular attention is paid to the traces of tools used for manufacturing (hammering, browning, possibly rolling of the metal) that can be significant to evaluate the antiquity of the object.
The or by gamma rays.
A chemical analysis carried out directly on the surface of the object ( PIXE ) makes it possible to obtain the exact composition of the metal and to highlight the existence of trace elements present in the gold and potentially significant of an origin. It is also possible to perform an analysis by LA-ICP-MS , a more precise method of analysis, from a micro-sampling of metal.
The study of the surface of a massive sample by scanning electron microscopy ( SEM ) reveals the presence or the absence of old corrosion phenomena (dissolution at the grain boundaries) and makes it possible to determine the possible presence of deposits, their nature. as well as corrosion products.
The study on microsection in optical microscopy and by SEM - EDX makes it possible to highlight an alteration gradient between the metal matrix and the surface (depletion of certain elements, dissolutions at grain boundaries, alteration cracks, etc.). and the presence or absence of surface treatments (enrichment in gold or silver, pre-Columbian "tumbaga" alloys for example).
This study also makes it possible to check the degree of refinement of the metal by the observation and the characterization of nonmetallic inclusions present.
+ In addition
The dating U / Th-He allows, sometimes with a large margin of uncertainty, giving the date of final melting of gold and therefore the achievement of the object. This recent technique remains relatively experimental and some gold objects do not allow reliable dating, usually because of an excess of helium in their structure."
http://www.labo-msmap.com/laboratoire-analyse-objets-or/
