Any question answered...

I have this lump of granite or quartz or something. It is 160cm x 60cm x 1cm @ 17kg!. I used to use it a wicked kitchen surface.

I want to ebay it but what is it?

Some kind granite or stone cladding? Any ideas what it is and how to describe it?

Ceramic floor tile?

list it as Stone Ceramic Work Top Surface Tile and give all dimension and weight and I doubt you'd have a problem