This is one of the two optional side quests available during the Perzel Farm Monsters quest. Note that this mission will expire once the Perzel Farm Monster quest is completed!

Client: Charles
Pay: 30 Mira, 2 BP, 5 Drill Meatballs
Bonus: None
Difficulty: Easy
Locations: Rolent Sewers
Enemies: Dirty Rat, Moth Cluster
Description:

I'd like someone to find my shiny rock. Please speak to me directly for details.

I think I might have dropped it behind the Melders Orbal Factory.

1. Charles says he's looking for a shiny rock he dropped somewhere.
2. He says he dropped it outside Mr. Rinon's shop, but when he looked for it there, he didn't find it.
3. Something shiny seems to have fallen through the sewer grate.
4. That means it's probably lying down in the sewers below.
5. The entrance to the sewers should be just behind the chapel.
6. Found a quartz fragment! It looks like this is the shiny thing we saw through the grate.
7. Returned the item to Charles.

This request is available on the Job Board as soon as Cassius leaves for his mission. Once accepting the job, find Charles behind the Orbal Factory. He'll tell you he lost his rock near the General Store, so start looking there. If you walk near the stores front, you will notice the "!" near the sewer grate. Investigating it will lead you on another merry adventure into the scenic sewers of Rolent. The entrance is in the southeast corner of town if you forgot. The area isn't too difficult to search through, but the item in question is near the locked gate at the far end, near the Training Mission chest. Just return it to Charles, who will give you 5 Drill Meatballs, then collect your reward from the guild.