Hard White Crystal Used in Clocks
Puzzle 14 of Fabric Arts Medium Pack
Question is: Hard White Crystal Used in Clocks
and the answer is: QUARTZ
Word Meaning:
QUARTZ — (mineralogy) 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.
Definitions from Wiktionary.