Crystite

Crystite is a material used for personal equipment by characters level 60 or below. From tutorial No. 40:

Crystite is a very rare ore found only in one mine in all of BatMUD. It is used to make duplicates of magical items which are almost indistinguishable from the originals. The mine is located in Dortlewall, continent of Laenor. You gain credits for the crystite store when you deposit crystite pieces at the crystite trading post. It is located in the southeast corner of Crystite plaza in Dortlewall.

From help getting started:

One good way to get usable items is to acquire crystite and use it to buy crystite items in Dortlewall. These items are somewhat powerful and they are personal and you can use them as long as you are level 60 or below.

Entry to the Crystite mine is limited to characters level 40 and under.