I am curious if there are any unique harder materials that you enjoy dildos or plugs being made out of.

Currently my list of harder material liking goes in this order: (Although not "unique")
Glass
Metal/Aluminum
Acrylic
Plastic

Some unique harder materials which I have heard of are: Ceramic, Granite, Marble and wood.



Some which I have found (but have yet to buy and try)

It appears this site sells some interesting ceramic ones: link
Plastic

Here are 2 granite dildos I have seen various places around the web:
link
link


Some custom "stone" dildos: (do a search here for "stone")
link

Small & Large granite plug:
link


Have any of you found any (and possibly have bought) ?