The halogen light bulb is a more advanced type of incandescent lamp which uses a halogen gas in order to increase both light output and rated life. Both halogen and incandescent lamps operate with a filament which heats up and glows when electricity is applied. The filaments are typically made of the element tungsten. Most halogens lamp burners and capsules are made using quartz glass. Today, halogen lamps are known for moderate efficiency and quality of light with high color rendering CRI of greater than 90%. Halogen lighting uses around 20-30% less energy than incandescent light bulbs.