素材
quartz inversion
Japanese: 石英転移
A phase transition in which quartz instantaneously expands and contracts at 573°C. This is related to cracking in shelf boards and plaster molds.
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Quartz inversion is a phenomenon in which quartz (SiO₂) undergoes a change in its crystal structure at approximately 573°C (α-quartz ⇔ β-quartz). Since this transition is accompanied by a sudden change in volume (approximately 2%), there is a risk of cracking if refractory materials containing high levels of silica or certain glass-based materials pass rapidly through this temperature range inside the furnace.
At around 573°C, it is recommended to slow down both the heating and cooling rates. In particular, rapidly passing through this temperature range during the slow cooling process can cause cumulative damage to the shelf plates and furnace lining. Since glass itself is amorphous, a direct quartz transition does not occur; however, because the degradation of refractory materials affects the furnace’s lifespan, controlling this temperature range indirectly helps ensure the quality of the artwork.
This entry is written in Japanese by Rei Chikaoka and translated for readers outside Japan. If something reads oddly, the original is the source of truth.