The smallest unit of measurement of radiant energy.


The second most abundant mineral in the Earth's continental crust. In the lighting industry Quartz refers not to the naturally occurring mineral but to "Fused Quartz" which is a glass material that consists only of 100% pure silica which essentially is sand. It does an excellent job of allowing ultraviolet light to pass through and has both a high working temperature and a high melting temperature (2000° C). The arc tubes of Metal Halide and Mercury Vapor bulbs as well as the capsule of many tungsten halogen bulbs are made from fused quartz.

Quartz Halogen

A Tungsten Halogen bulb with an inner capsule made of Fused Quartz.

See Tungsten Halogen Bulb.


The registered trademark that represents many DAMAR branded tungsten halogen bulbs.

Similar names exist for other manufacturers:
    Quartzline is a registered trademark of General Electric
    Capsylite is a registered trademark of Osram-Sylvania

    Until it was cancelled in 2005 Masterline was a registered trademark of Philips Lighting.