It's a silicon dioxide crystal,
otherwise known as QUARTZ.
The Big Bang Theory Season 12, Episode 2
What do we know
about QUARTZ?
The Big Bang Theory Season 12, Episode 2
this tourmalinated QUARTZ
that we got in the lab.
The Big Bang Theory Season 7, Episode 13
Oh, you forgot your QUARTZ.
The Big Bang Theory Season 7, Episode 13
Quartz, from the
German "quarz"
The Big Bang Theory Season 12, Episode 2