There is no way to get outside of the House of Madness to get the gems. Officially, anyway; I have not tried this there, but
Teleporting Anywhere, via hex editor.
EDIT: (a bit to the east of the House of Madness is the 4th level of Iona's dungeon)
map 00, X = 20 6A ; Y = 10 B5 - House of Madness
map 00, X = A0 6D ; Y = 10 B3 - outside, by the gems
not that there are not far easier ways to cheat, or anything <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />
The gems in the room with the holy sword were an illusion; no way to get them. If they are like most of the spell books outside the entrance to the House of Madness, they should show a zero weight when you move your mouse over them.
When you exited the dungeon you got a quest to rescue Zandalor (castle treasure room, sewer entrance), do so and he will teleport you to the council hall. Clear that area and you will find the imp who 'borrowed' your teleporter stones. After this you must gather the seven council members to get to the wastelands (which is a one-way trip, so complete all other quests before you hit the gong).
The holy sword is likely the best sword you can get before the wastelands.
VERY BIG SPOILER ON HOLY ITEMS
