noun / adjective
ruby
ROO-bee/rˈubi/
A red gemstone consisting of corundum.
A faceted ruby catches the light against a plain white background.
Etymology
The gem called rubi takes its name ultimately from a description meaning “red stone.” Its characteristic rich red color is thus the identifying feature preserved in the name.
In context
if you want a large red stone, you're probably far better off with garnet than with with ruby.