Crystal

File:Resource crystal.png Crystal is one of the four magical resources in Heroes (along with Gems, Mercury and Sulfur). Crystal is needed for several buildings, recruiting Green Dragons, Gold Dragons, Ancient Behemoths and Crystal Dragons. The primary source of Crystal is the Crystal Cavern, which brings its owner 1 unit of Crystal per day. You can also find Crystal scattered around the land in small amounts (3-6 units of Crystal per resource stack).

In Rampart town you can also build the Resource Silo which will bring you 1 Crystal per day.

Sephinroth, a Warlock, is able to produce 1 additional Crystal per day for the Kingdom she serves. Also, any hero equipped with the Everflowing Crystal Cloak gives you 1 Crystal every day.