Piezo ignitor pulse shape?

I would like to know the pulse shape of the piezo ignitor from a BBQ
lighter, but I haven't got an oscilloscope. Is it AC, a single
monopolar pulse, or a bipolar pulse, or a dampened oscillation?

Probably the pulse shape depends on its design, so I dissected the
piezo ignitor of a BBQ lighter. Please see the image at
http://s365.photobucket.com/albums/oo98/jkien_photos/?action=view&current=IMG_6175.jpg
.. The piezo electric body is apparently composed of two parts: the
major part is a cup or a bottom, probably made of brass. Question: is
this just backing material? The minor part is the grey matter inside
the cup. The grey matter doesn't have a distinct shape. Question: is
the grey matter inside the piezo ceramic (PZT)?