You analyze your mithril pendant and sense that the item is largely free from merchant alteration restrictions.

The creator has also provided the following information:

The mithril pendant is an Illusion Prop that will project minor illusions around you when worn.  It is set to:

  Adds "He is surrounded by a circle of crackling lightning." before the appearance of your health.

  The mithril pendant can be hidden or revealed when covered.

You get the distinct impression that the mithril pendant itself may freely be altered by almost any merchant, but not the illusions that it creates.

You get no sense of whether or not the pendant may be further lightened.