In the gemstone market, opal is a very special and unique gem, thanks to its play of color. But the opal has a significant defect, some can destabilize, with a loss of transparency (whitening) or integrity (fracturing). This phenomenon of destabilization is correlated with dehydration, the loss of water being contained in the opal.

The destabilization of opal can only be understood by studying how water integrates into amorphous silica. Thanks to the latest developments in spectroscopic and thermal analysis methods, it is possible to assess the size of the pores containing water in the microstructure of the opal. By applying these measurements with destabilization experiments on a range of samples, the physical mechanisms driving the destabilization were identified. The theoretical tools allowing to model these mechanisms open the possibility of predicting the destabilization of an opal.

This research, still in progress, will make it possible to put in place practical tools to evaluate the sensitivity of each opal to destabilization.