World profile
Act 2 The Wild Planets
9 Crystal Mine
a cavern where crystals glow in the dark
Underground, a big cavern opens up in front of you. Purple, pink and blue crystals glow in the dark, and lanterns light up a wooden bridge. Hop in the mine cart: here we go!
Your dino ally
Stegosaurus
It helps you only in this world
In the game
Race through the tunnels in a mine cart: the Stegosaurus's plates light up the dark.
- A big underground cavern
- Glowing purple, pink and blue crystals
- Lanterns and a wooden bridge
- The Stegosaurus and its glowing plates
Its light Underground, glowing crystals.
In real life
The cave of giant crystals
In 2000, in Mexico, two miners digging a new tunnel discovered a cave full of giant crystals. It is 300 meters underground, under the Naica mountain. [1]
These crystals are made of gypsum, a mineral that lets light through. The biggest ones are about 11 meters long. [1][2]
They grew in hot water full of minerals, over hundreds of thousands of years. [1]
They grow very, very slowly: at the slowest rate measured by scientists, a crystal takes more than 2,200 years to grow just one millimeter. [2]
Sources
The information on this page comes from these sources:
- Giant Crystal Cave's Mystery Solved, Stefan Lovgren, National Geographic, 2007 (accessed November 5, 2026).
- Bigger than a house, crystals take eons to grow, Charles Q. Choi, NBC News (LiveScience article on the work of Juan Manuel García-Ruiz, published in PNAS in 2011) (accessed November 5, 2026).