All natural stone are porous natural stone, it would need to be seal annually or permanent to prevent from stains. The sealer does not change the look of the stone. Quartz and Recycled Glass are man made options that are more durable than natural stone. They are made with concrete, epoxy, glass fragments, and a colorant. They are also more environmentally friendly than natural. The slabs tend to be more consistent in look versus natural stone. Quartz or Recycle Glass are well known for maintenance free, it doesn’t required to be seal. Starting price is higher than natural stone.