SOLVED. Middle Grade Sci-Fi: Poor town powered by crystals with a cave discovery by children. Spoilers ahead. [s]

[Willow Anne]

Read it somewhere between 2016-2019. I believe that the cover was black with a blue crystal/gem right in the center of it. This was the first book in a series.

The main characters were a group of kids who lived in a poor town that was powered by crystals. The kids find an underground cave with lots of the crystals and they use them to power the town and trade with a merchant for anything they need (pots, horses, food, etc). The merchant usually comes every month or so (I think) to trade.

[Rainbowheart]

The Diamond of Darkhold?

[Willow Anne]

Yes, thats it! Thank you!

[Rainbowheart]

Great, glad to help out!