Ruby is the red variety of Corundum, the only mineral with a hardness of 9 on the Mohs Hardness scale. Ruby, at it’s finest, is nearly as alluring as the One Ring. Have you ever accidentally cut yourself and then see a small, bright red drop of blood and imagine that color set in a gold ring? That is the color of Ruby at it’s finest, and once, have I seen Ruby in person, at it’s finest. Maybe a year or so ago I was walking around in our Church during fellowship hour when something caught my eye, (nowadays that happens a lot, me just walking around when a beautiful gem catches my eye) it was maybe a ten or fifteen-carat Ruby, translucent, blood-red, and table cut, set in a ring. I walked over to the wearer of this gem and talked to her about it, asked if it was a real ruby, and so on. Unfortunatley, I couldn’t get a photo then, and she moved away not long after. 😦
Rubies are colored red from the presence of Chromium Oxide. Rubies, like Emeralds, are rarely flawless, though sometimes there are so many inclusions in the right place that they reflect light in the form of a six-rayed star, creating a star ruby.
Garnets are very similar, if not exactly, the color of ruby, and are sometimes mistaken for them. Spinels can be exactly the color of Ruby, and are often used to imitate them, being called Balas Rubies. In fact, the Black Prince’s Ruby in the British Royal Crown is not a Ruby, but actually a Spinel! Rubies, though, have a hardness of 9, which no other Gem (except, of course, Sapphire) shares.
People have discovered how to Lab-grow Rubies, but those rarely have flaws. The second photo may be a synthetic (lab-grown) Ruby.