the palantir of Amon Sul

One of the greatest artefacts ever wrought by mortal hands, this palantir is
considered one of the greater stones, both because of its size and its power.
It is a large spherical stone nearly three feet across, of a black crystal of
unknown composition. The surface of the palantir is perfectly smooth and there
are no marks to suggest any orientation. Yet, what lore one has gathered tells
you that if one can master the stone, then all the lands around are yours to
survey. Around the base of the stone runs a delicate silvery cradle, providing
a base upon which to sit the palantir.

It is the palantir of Amon Sul.
It radiates a magical aura.
It weighs seven stone and twelve pounds.

You identify the palantir of Amon Sul.
It is an enchanted, blessed, and unsellable object.
It weighs seven stone and twelve pounds, and it is worth about 250 lauren.
Its keywords are palantir, crystal, sphere, cradle, and stone.