Crystalline Mineral Composed of Silicon and Oxygen
This page is the CodyCross answer for the clue below from Top Secret, Group 2095, Puzzle 4 (Spycraft Training).
Question is: Crystalline Mineral Composed of Silicon and Oxygen
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.