My name is Maud. Starlight Glimmer gave me this hour to try out my new stand-up routine, because all forms of art are equal. I've been practicing. I'll also explain the joke for those who don't understand it so that we can all laugh together. Read my jokes after the break.
What is Princess Luna's favorite rock?
Basalt.
It's funny because basalt is the most common rock on the moon, and Princess Luna was imprisoned there.
If Spike eats gemstones, does that make him a murderer in a different Universe?
This joke aims to draw upon public knowledge of another popular show with a similar demographic. It implies that gemstones have a different place in other societies, such as being main characters that Spike would eventually eat if he were to cross over into another world. That's my favorite joke.
Two ponies are digging up near a volcano. One pony turns to the other and says, "this rock is tuff."
This joke is funny because it's a homophone of the word "tough." Tuff is a rock that is created during a volcanic explosion, so the aforementioned ponies are cleaning up after it. We are willing to suspend our disbelief that the ponies are still alive after the massive amount of gas because this is a joke. But we can always imagine that the ponies teleported to the volcano after the explosion.
...
That's Marble's favorite joke. It's funny because jokes usually have words in them, but there were no words in that one. Marble also doesn't talk, but I do understand her disassociation with the intricacies of a pony's psyche.
I like my limestone the way I like my Limestone: at the bottom of an ocean.
This joke is revenge for Limestone hiding Boulder from me. It implies that I want one of my family members to be drowning because limestone grows there. I want to let everyone know that I would never wish that Limestone be at the bottom of an ocean when it is not in a joke. Especially since limestone usually forms in shallow and warm waters, which renders this theoretical joke a semantic impossibility. I tried out this joke for your reaction, because the shock factor usually doesn't make you think about the logical inconsistencies.
Finally I have a haiku for you all:
I have a degree
Rocktorates have a saying
Extra fries with that?
It's funny because a rocktorate is a very distinguished degree that takes years of studying, but this current job market is volatile and has no promises of finding a job for graduates. I don't want any of you to worry, though. I am only in a minimum wage job during the duration of this joke, and that length of time has passed.
Starlight Glimmer is telling me that my time is up. Thank you for laughing on the inside, and I hope my explanations helped you understand the jokes.