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

Well, what makes them different is their chemical makeup and the way they’re formed.

For example, sapphires and rubies are both made from a mineral called corundum. Sapphires are usually blue, but they can also come in other colors like pink, yellow, and green. If a corundum gem is red, it’s called a ruby.

So, basically, the only thing that makes a red corundum gem a ruby instead of a red sapphire is its name. It’s still made from the same mineral as a sapphire, but it’s just called something different because of its color.

The same goes for other gems too. Emeralds are made from a mineral called beryl and diamonds are made from carbon. They all have different colors and properties based on what they’re made of and how they’re formed.