Jagged sparkly knife
From The Discworld MUD Wiki
A jagged sparkly knife costs A$50, it looks like:
This is a fairly bulky knife. One edge is very jagged and rough, but the whole knife sparkles, and it looks like it would be very hard to damage. The handle is white and smooth. This might be just the sort of thing to keep on you to help you out of a tricky spot, or maybe to open envelopes, though it looks like it would probably shred the contents, too.
