The ruby ring your grandmother left you has always been your favorite. Even when you were young, you couldn’t help noticing it when your grandmother wore it. Of course, there was often mention of its size. “It’s a 5 carat ruby, the finest pigeon blood red color.”. So you know it must be worth a small fortune.
How your grandfather paid for this near priceless ruby ring on his $3,500 a year job as an accountant you’re not sure. Now it’s yours and you must decide whether or not to “cash it in” or maybe reset the ruby in a new mounting for your wife. Before you start spending a lot of time picking out a new sports car or telling your wife she’s about to become your town’s new Queen Bee, you might want to first determine if your grandmother’s ring is in fact a real ruby or a cheap man-made piece of synthetic corundum (the mineral natural ruby is cut from) or worse yet, a piece of colored glass! Here are a few tips on determining if your newly inherited ruby is indeed a real, natural ruby.
Buy a 10 power (10x) jeweler’s loupe online and examine your “ruby”. Bob created a Youtube video a while back that helps explain how to use a loupe.
Flaw are the fingerprint of every gem. They can help us identify one gemstone from another and can help us determine if a gem is natural or man-made. We do this by looking for flaws or imperfections that might otherwise be invisible to the naked eye. If you see any “air bubbles”, you’re probably looking at a fake because bubbles don’t form inside a natural ruby. More likely, you’ll see no flaws or extremely small, almost invisible flaws, which is typical of all lab-created gemstones.
If you detect feathery, feather is a small crack or fracture that may disappear when viewed from certain angles, or fingerprint looking flaws, there is a good chance your ruby is real, although lab-grown rubies can have very “real” looking inclusions.
For a positive, professional determination as to the authenticity of your ruby’s origin (natural or man-made), your best bet is to take your grandmother’s (now yours) ruby ring to a GIA or equivalent certified gemologist to determine if your ruby is indeed a real, all-natural ruby or a man-made fake.

Indiana University Alumni : GIA Graduate Gemologist Student