The Crystal Cavern

Ores
The ores that can be found here are as follows: copper, iron, silver, gold, sapphire, emeralds, and blue crystals.

Blue Crystals
With a basic selling price of 1000 C these are the best ore to mine, they are found in a cavern behind the door locked by a chain, you can unlock the door with the wire cutters you find in Crimson near the one of the shops.