eli5 What determines whether a gem is a sapphire, ruby, emerald, diamond, etc if those gems don’t necessarily have to be the most common thought color? For example, sapphires can be colors other than blue. What’s the difference between a red sapphire and a ruby?

Question

eli5 What determines whether a gem is a sapphire, ruby, emerald, diamond, etc if those gems don’t necessarily have to be the most common thought color? For example, sapphires can be colors other than blue. What’s the difference between a red sapphire and a ruby?

In: 5800

Answer 1

The difference is that they are different kinds of minerals. A ruby is a red or pinkish version of the mineral corundum (aluminum oxide), while other colors are called sapphire. A red sapphire is the same thing as a ruby.

But an emerald is the mineral beryl with trace amounts of chromium or vanadium turning it green. Diamonds are a form of carbon arranged in a diamond cubic crystal structure.