Host: The Gemmological Society of Japan
The sol-gel method of synthesizing silica glass from a liquid raw material is a simple experiment that can be performed at room temperature without heating. One experimental system can be used to give assignments for each student's goals. For example, simple operations such as reagent metering and mixing, comparison of catalysts, understanding of hydrolysis reaction and dehydration condensation reaction, understanding of light interference based on observation of play of color effect, yield from final product Calculation. It takes about two weeks before the synthesized silica glass precipitates and can be confirmed. This time, while trying to compare the products by catalysis in the experiment class, authors explained the play of color effect of gem opal and the structural color of insect wings.