Are there any visual differences to a heated versus unheated ruby? Or heated versus flux healed ruby?

[Indylady]

Certain types of rubies seem to have certain looks. For example, the heavily treated BE rubies have a certain crisp and pure red look to them, sometimes orangey red, and a lot of of the flux healed rubies have a kind of glue-y look. Do you think unheated rubies look different in any particular way? Or traditional heat only rubies?