Blue fused glass pendant measuring 42mm high x 20mm wide. Top drilled. The art of glass fusing is the process of joining pieces of glass together in a kiln until the glass fuses at approximately 1490 degrees Fahrenheit, and cooled very slowly. The incredible shine is caused by using dichroic glass, which is a type of manufactured glass designed to change colors under different lighting conditions and viewing angles. The word dichroic comes from two Greek roots: “di” meaning two and “chroma” meaning colors.