This video shows a egg shell being heated to 800℃ using a halogen point heater.

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Heating, melting and vitrification of rocks series 20 – Silicone shell (Chrysocolla) Heating of a seashell Heating of emerald (Nanosital) Pinpoint heating of 0.5mm mechanical pencil lead Heating of the tile Heating of the refractory brick Heating purified water on a silicon wafer Heating, melting and vitrification of rocks series 23 – Sandstones