0en2oh 4 years ago ReplyUpvoteyou can actually melt glass in a microwave quite easily. The material in the microwave kiln is a microwave susceptor. Typically, this is silicon carbide, available as a powder. It's mixed with refractory material. Once the glass becomes hot (as a result of the hot silicon carbide), it actually becomes a microwave susceptor. The hot glass will begin to glow red, eventually melting under the effects of the RF energy.