This is available to all (unless you live in the North - you'll find out in book two).  Using the Equanime that resides in all, it can be utilised to deliver a devastating blast. Even the Fifth Generation can splinter a stone with its full blast. Good luck facing a first.

Taylan's facade. One of Taylan's many discoveries, or inventions, depending on your point of view. He discovered that the amaya stone held transformative properties. It could transform an object into a likeness of something else for a limited period of time (time dependent on stone size).  The object used during the transformation will retain its feeling (to touch) and weight. So if you are trying to fool someone with it - you need to be careful. 

It does what is says on the tin. Upon release, the arrow will multiply up to fifty times depending on equanime strength. It should go without saying that this should only be used in exceptional circumstances, whereby only the enemy may fall victim.

This stone has  retention properties, effectively acting as a handy suitcase. When casting, covering it with equanime, looking at the object of choice and creating  a mind key, an object can be stored within the stone for later retrieval; this in itself causes problems. The stone has quirks. When retrieving the object, its colour can change. You also have memory issues - not the stone's problem, but the keepers. If the keeper can't remember what has been stored, it could be lost forever. They also have to remember the key. There is also the highly

unlikely, but not impossible scenario that the keeper could inadvertently think of an object and key at the same time and cause the stone to release an object. 

Not in book one. Remembered in book two. Rocks have the property of remembrance.  You can go up to any rock of note, recall a time and the rock will show a snapshot. It's a picture of that moment. Whilst useful, you have to be specific - you  need to know the exact time and date of an occurrence in order to recall it. You can quickly skip through images, but if you aren't within hours, you could be there for days, perhaps longer, trying to find the exact image in time you want.

Oh so many: 

An ancient curse. It causes the target to slowly lose their mind, literally. First there's confusion, and amnesia, before loss of bodily control. At its height, the body will be left a shell. If fed, watered and cared for it can last millennia, but the mind will be wandering the stars, lost for eternity. The only known cure is if the curser recinders, or dies.