Vivianite

Vivianite is a crystal that is only found in the strongholds of the Vivianite dwarves. The dwarves are named after the crystal. It has pink and purple segments, and is slightly cloudy in coloration. It also has special healing properties once it has undergone a specific binding process with organic matter.
The Vivianite dwarves do keep this process a secret, so it is unknown if it only works on dwarves or if other races or even creatures are even capable of undergoing the procedure as well.