Which type of lamp is characterized by a tungsten filament and a quartz envelope?

The correct choice is based on the unique characteristics of halogen lamps. Halogen lamps contain a tungsten filament similar to incandescent lamps; however, they are distinguished by their use of a quartz envelope rather than regular glass. This quartz envelope allows the lamp to operate at higher temperatures, which enhances the lumens produced while extending the lifespan of the bulb. The halogen gas inside the envelope facilitates a chemical reaction that redeposits evaporated tungsten back onto the filament, further increasing efficiency.

In contrast, incandescent lamps do use a tungsten filament but do not have the quartz envelope, leading to limitations in heat handling and efficiency. CFL (Compact Fluorescent Lamp) and LED (Light Emitting Diode) lamps do not utilize a filament system; instead, they rely on entirely different technologies for producing light. Thus, the defining features of a halogen lamp make it the correct answer in this context.