First of all lets tackle Heirloom. Acccording to wikipedia: In popular usage, an heirloom is something, perhaps an antique or some kind of jewelry, that has been passed down for generations through family members. So it may or may not be an heirloom.
Second that could (or could not) be a ruby, it looks like one, it is the form of the crystal that someone cut an polished en cabochon. Very Cool! Have you done any testing? R.I>? or Specific Gravity?