I have been carrying these for a long time and I couldn't find what to do with.
Could you?

Pammel jewel of equilazer
Broken sword
3 Pieces of burial mask (how many should I have by the way?)

Pommel Jewel - can't remember when, but you get the hilt and the blade. Take them to Cromwell and he'll build the Equalizer for you.
Broken Sword - Haven't seen it.
King Strom's Burial Mask - You have to defeat all of the djinni/efreeti in the Windspear Hills dungeon. After you have gather the pieces, the are automatically formed into the mask. It let's you see an invisible guardian that protects Strom's tomb.

you get blade and hilt in underdark (ch.5 or 6) so hold onto pommel jewel. disappears if you sell it.