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.
The Ruby Tear was created in 1997.
Kaitō Ruby was created in 1988.
Ruby Pipeline was created in 2010.
The Ruby in her Navel was created in 2006.
The Ruby in the Smoke was created in 1985.
Ruby Records was created in 1981.
Ruby Button was created in 2011.
Ruby Allen was created in 2005.
Ruby Lane was created in 1998.
Ruby's Torch was created in 2006.