What are Pixie Diamonds?

This is a question heard many times within new players. How do you earn them?
Pixie diamonds are earned in two ways:
1. Purchasing/buying them (you will get more pixie diamonds this way)
2. Levelling up (Which will not be easy!)

Note that there are not money makers/cheats to earn diamonds. All third parties don't work :-)

Once you purchase pixie diamonds, have fun shopping!!