Definition
A high-purity glass made almost entirely of silicon dioxide (silica), formed by melting natural quartz crystals or refined silica. It withstands very high temperatures, resists thermal shock, and transmits ultraviolet light well, which makes it useful in instruments, lamps, and optical components where ordinary glass would fail.
Plain English
A special type of glass made from melted quartz. It can handle much higher temperatures than normal glass and lets ultraviolet light pass through it.
Context Anchor
Seen in aircraft maintenance and equipment discussions, especially around lamps, light covers, instrument parts, or other clear parts exposed to heat.
Derivation
Quartz comes from the German Quarz, the name of the natural mineral made of silica. Calling the material 'quartz glass' simply tells you the glass was made by melting that mineral, which is why it keeps quartz's heat resistance.
Why Pilots Care
Components like landing light bulbs and certain sensors use quartz glass because they get extremely hot in service. Knowing the bulb envelope is quartz is also why technicians avoid touching it with bare fingers — skin oils can cause it to fail when heated.
Intuition Check
Do not read “quartz glass” as just fancy ordinary glass. The important idea is heat resistance: it is clear like glass, but much better suited to hot aircraft parts.
Example Sentence 1
The landing light uses a quartz glass envelope so it can tolerate the heat of the filament without cracking.
Example Sentence 2
Because quartz glass resists thermal shock, it is preferred for instrument windows located near engine compartments.