It originates on a planet called Coba, a former colony of the Ruby Empire that became isolated during the empire's collapses and remains so even during the time of the novels.
Ruby | Ruby (programming language) | Ruby Dee | Ruby on Rails | Jack Ruby | Andrew Dice Clay | ruby | Dice | Ruby Wax | Pokémon Ruby and Sapphire | Ruby Vroom | Ruby Turner | Ruby Ridge | ''Pokémon Ruby'' and ''Sapphire'' | Shenzhen Ruby F.C. | Ruby Murray | Ruby-crowned Kinglet | Ruby Braff | Tom Dice | The Tale of Ruby Rose | Ruby Walsh | Ruby-Spears | Ruby Records | Ruby Payne-Scott | Ruby Laffoon | Ruby Junction / East 197th Avenue | Ruby, Gold and Malachite | Ruby character | Ruby Bridges | Mark Dice |