It's a material that resembles a ruby but is man-made (synthetic).
Ruby - Ruby album - was created in 1976.
Brazilian Ruby was created in 1783.
Kaitō Ruby was created in 1988.
Ruby's Torch was created in 2006.
Ruby Romaine was created in 1996.
Mourning Ruby was created in 2003.
Ruby Lane was created in 1998.
Ruby Joe was created in 1996.
Ruby Pipeline was created in 2010.
The Ruby in her Navel was created in 2006.
Ruby Buckton was created in 2008.
Fort Ruby was created in 1862.