Crystallization deterioration is a unique form of decay affecting certain Venetian and German glass from the 16th and 17th centuries.
Crystallization deterioration is a process that affects some Venetian and German glass from the 16th and 17th centuries. It begins with microscopic cracks that gradually expand, leading to surface flaking similar to dandruff. Over time, the glass appears to sweat, becomes 'slimy', and eventually crumbles.
This decay process, currently without a remedy, should not be confused with the iridescence of excavated glass, which is only superficial, or with devitrification. It occurs only in certain types of glass because Venetian glassmakers, in their quest for pure and brilliant crystal, purified the ash before adding it to the silica sand. This process removed much of the calcium and magnesium, which served as stabilizers, from the frit.
Similarly, some recent Italian and Scandinavian crystals show signs of degradation due to excessive refinement of raw materials.
Frequently Asked Questions
- What causes crystallization deterioration in glass?
- It is caused by the removal of stabilizing elements like calcium and magnesium during the purification process.
- Is there a remedy for crystallization deterioration?
- Currently, there is no known remedy for this type of deterioration.