Today’s post is a riddle. Here are close-up pictures of one of the most beautiful rare gems known to man.

It can be sculpted but will easily crumble.

Its beauty can be harnessed but not directed.

It can be tamed but never slaved.

It can be sold but color decreases its value.

Blues are the less expensive but most valuable.

Who can tell me exactly what it is and where to find it?