Slate slabs are generally small compared to marble and granite so more seams will be necessary to complete a kitchen project. In fact, many slate quarries are limited to tile production because of the sizes of usable material that exist. Most slate is quite porous and combined with its natural cleft layers, make its use in outdoor and wet applications such as showers tricky, so be sure to do your homework before making this decision. On a more positive note, slate is very resistant to chemicals, so in an indoor kitchen setting it can perform quite well. Though you may experience some flaking or chipping away at the layers.