1. Must be natural
2. A nonliving solid
3. Must have a definite chemical structure
We also learned that crystals have a repeating pattern in the particles that create it.
The key is the repeating pattern.
We watched a video about Las Queva de las Crytales. Here we see that crystals can grow to be huge if the environment is right.
We then looked at how Mohs hardness scale works.