colorless glass made of almost pure silica
"The geologist held up a piece of clear quartz, noting how its transparency revealed the purity of the silica within."
a hard glossy mineral consisting of silicon dioxide in crystal form; present in most rocks (especially sandstone and granite); yellow sand is quartz with iron oxide impurities
"The geologist identified the white, crystalline grains embedded in the granite as pure quartz."
The most abundant mineral on the earth's surface, of chemical composition silicon dioxide, SiO₂. It occurs in a variety of forms, both crystalline and amorphous. Found in every environment.
"Quartz is the most abundant mineral on Earth's surface, composed of silicon dioxide and found in every environment from crystals to sand."
In plain English: Quartz is a very hard and common mineral made of silicon dioxide that you often find inside rocks.
"The watch has a quartz movement that keeps very accurate time."
Usage: Quartz refers to the hard, crystalline form of silica found abundantly in rocks and used widely in electronics as an oscillator component. Unlike amorphous glass or other minerals like feldspar, it possesses a distinct geometric structure that allows for precise timekeeping applications.
The word quartz comes from the German Quarz and originally meant "hard," a meaning shared by related words in Polish and Czech. It traveled into English through Middle High German while retaining this sense of hardness that traces back to ancient roots about enclosing or grabbing.