Gems called rubies are used in lasers.

Well, it's true that the FIRST successful laser was a cylinder of ruby.
I silvered the ends of a ruby and built a laser in my sophomore
Physics lab in about 1960 or so.  But I think other substances have
successfully and routinely made to lase since then, and I'd be
surprised if rubies are ever used for the purpose anymore. 

In fact ... you or somebody you know probably has a laser pointer,
no bigger than a pen, that you can buy for a few bucks and carry
in your shirt pocket.  That pointer, as well as the lasers used in
fiberoptic communication, uses a laser diode that's the size of an
LED and runs on one or two double-A batteries.  In the one that
I made more than 50 years ago, the ruby alone was the size of two
double-A batteries, and it took a roomful of other stuff to convince
a few anemic photons to dribble coherently out of it now and then.   

There is some truth that rubies are used in lasers. The ruby laser was the first laser created using faux ruby crystals as a medium. It was developed by Ted Maiman in May of 1960.

Friction is the force that act and opposes all motion of moving objects