Definition
A precisely cut slice of quartz that vibrates at a highly stable, predictable frequency when an electrical voltage is applied across it. This piezoelectric effect is used in aviation electronics to control the operating frequency of radios, navigation receivers, and timing circuits.
Plain English
A small, carefully shaped piece of quartz that shakes back and forth at a very steady rate when electricity passes through it. That steady shaking is used inside radios and other equipment to keep them tuned to the exact right frequency.
Context Anchor
Seen in discussions of aircraft radios, navigation equipment, transmitters, receivers, and electronic maintenance.
Derivation
From the German Quarz, the name of the mineral, and the Greek krystallos meaning 'ice' or 'clear, frozen.' Early observers thought clear quartz was a permanently frozen form of ice. The name reminds you it's a clear, glass-like mineral -- not a manufactured electronic part, but a natural material harnessed for a useful electrical property.
Why Pilots Care
Provides drift-free frequency stability in communication and navigation radios, ensuring reliable signal reception and accurate instrument readings.
Analogy
Think of a tuning fork. Strike it and it vibrates at one exact musical note, no matter who hits it or how hard. A quartz crystal does the same thing electrically -- give it voltage and it vibrates at its one exact frequency.
Intuition Check
A quartz crystal is not just a decorative crystal or a piece of glass. In this context, it is a working electronic part used for steady timing and accurate tuning.
Example Sentence 1
The quartz crystal in the comm radio holds the selected frequency steady, even as cockpit temperature changes during the climb.
Example Sentence 2
The technician replaced the cracked quartz crystal in the navigation receiver to restore stable signal output.