We're talking about stone in general. Volcanic stone is one type of stone, which does not cover all of the applications of stone as used in buildings, masonry a

We're talking about stone in general. Volcanic stone is one type of stone, which does not cover all of the applications of stone as used in buildings, masonry and other industries today. I also specifically addressed volcanic stones in a sister comment. Some rate of formation is not enough to satisfy the commonly held definition of renewable resources. Google "is stone a renewable resource" for a jumping off point.