Is a ruby heavy for its size?Is it attracted to a magnet?Can it be scratched with a nail or other minerals?

It is quite heavy for its size having an S.G. of 3.96 to 4.01 as compared with Quartz at 2.65 to 2.66 It is in no way affected by a magnet. It is the second hardest mineral on the Mohs' scale and can only be scratched by a diamond which makes it an excellent stone for rings which get a lot of wear.