不良・失敗
devit nucleus
Japanese: 失透核
The origin of opalescent crystals. Surface scratches, grease, and dust act as nuclei.
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A devitrification nucleus (devit nucleus) is a microscopic crystalline nucleus that forms on the surface or within glass and serves as the starting point for crystallization. Once formed, it promotes crystal growth during subsequent reheating, causing cloudiness and surface roughness (devitrification) to spread. Devitrification nuclei are caused by factors such as “scratches, contaminants, or residues from previous devitrification.”
To prevent the formation of crystallization nuclei, it is crucial to keep the glass surface clean. Since touching the glass with bare hands can cause skin oils to act as crystallization nuclei, cotton gloves should be worn when handling it. Additionally, designing a firing program that quickly passes through the temperature range (around 700–750°C) where nucleation is most likely to occur is also effective. Once glass has undergone loss of transparency, it cannot be fully restored even through refiring.
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.