It is not a mystery it is the gas piping out of your joint when you pop them if you push down on them. If you pull on your fingers then it is your joint being pulled out and put in. If you push on your fingers it is better than pulling because pulling can cause joint damage.
Answer:
It will bend and grow towards the hole because the sunlight will shine through the hole and the plant will sense it so it will grow towards the light. I hope I could help you :)
Explanation:
These rocks are called Foliated rocks.
