The friends arrive at the gates of the Emerald City but do you know what an emerald is or how it was formed?
Explore these websites and videos to find out more about emeralds and other precious gemstones.
How a diamond is formed, plus other cool rock facts
Birthstones are the gems that represent the month of your birth. The idea of birthstones goes way back to the 1st century but a formal list was created in the early 20th century.
The science and legends of birthstones
Challenge yourself!
Try this personality quiz to find out what gemstone suits your personality. Is it the same as your birthstone? These quizzes are just for fun, but do you think it was right?
You can also look at the Help with Challenges page to come up with your own gemstone challenge.
