A very hard, nearly opaque gem. Looks sort of like milky quartz with just a hint of transparency. They naturally glow ever so slightly, though not enough to be useful as a light source and only notable in dim lighting. Theal is Gerenshuge for "light". Comes in an assortment of pale starlight colors; grey, creamy, sky blue, yellow-orange. Pure white is rare but worth about three times as much.
Found in the remains of some shadow creatures, such as nimbi, they very rarely will be found with seordstone impurities. Like their cousin the seordstone, thealstones are useful in enchanting. They are a viable substitute for the Mirkik Sokis enchantment.
This material must be provided for alterations.