Abstract:
Museum specimens of pyrite are known to undergo oxidation even during storage. Characterisation
of the oxidation products is however not always simple due to amorphous character and varying degrees
of hydration of the oxidation products. This paper presents an alternative approach to the characterisation
of oxidation products by identifying their presence from their characteristic thermal decomposition
processes using thermogravimetric and evolved gas analysis. Four pyrite specimens
were characterised with varying degrees of oxidation. Iron(II) and iron(III) sulphates were also characterised
for comparative purposes. The degradation products were observed to correlate well with
the presence of iron(II) sulphate even though there was found to be some discrepancy in the higher
temperature decomposition reactions.
