As two actions, you touch a stone object of Medium size or smaller or a section of stone no more than 1 meter in any dimension and form it into any shape that suits your purpose. So, for example, you could shape a large rock into a weapon, idol, or coffer, or make a small passage through a wall, as long as the wall is less than 1 meter thick. You could also shape a stone door or its frame to seal the door shut. The object you create can have up to two hinges and a latch, but finer mechanical detail isn’t possible.
You can manipulate an object of 1 larger size (Large, Huge, and Gargantuan) and the section of stone by 1 meter in any dimension for each additional mana or psi expended.