Obtaining a diamond from the Labyrinth:
From the Mighty Goblin, go 1 south, all west, and all south until you encounter Gwyllem, the Enlightened One.
He'll ask you this riddle:
'I am sometimes raging as a bull and sometimes calm as a baby sleeping.' Gwyllem, the enlightened one says. 'I have two banks but never any money. Who am I?'Sayto him "River".
You will be sent south from Gwyllem. Be careful not to return this way unless you need to, or you will have to do the riddle again. Then go all south, 1 east, north, east, south, and pick up the Black Mushroom on the ground. Then go north, east, 2 south, west, south, east. You will see Leoric. Try going east and he'll ask for a mushroom. Give him the mushroom and you will be sent east of him.
From there, you go 4 east, north, east, north, 2 west, north, west. You will encounter Salem the necromancer. Search in his room and try to go north. He'll say:
Salem says, 'Ye must find me a diamond before ye can speak with Acron; follow the sphere and you will find a diamond.' Salem utters the word 'gnyah!' The air shimmers and a green sphere appears.
It is VERY IMPORTANT that you watch what direction the orb moves and follow one step behind it very carefully. The orb will float on through a number of rooms and end up floating through a south wall. Search, enter, and pick up the diamond in there. Bring this back to Salem.
Give the diamond to Salem and he will transport you to the room north. West of here is Acron! He is in a safe room, and there is a down room that sometimes holds goods such as a meteorite slab. Acron usually rewards low level visitors with small amounts of practices.