Ever wonder where all this stone comes from? As I've noted, most of ours comes from Brazil, specifically northern Brazil. The Bahia region is noted for it's unusual offerings. From the pictures below, you can get an idea of the overall scope of the extraction. And, judging by the size of what is behind the current quarry, you can get an idea of how long the quarry will last. They are finite.
There are numerous quarries of some colors. Say, Santa Cecelia and New Venetian Gold. Same for Ubatuba, which was named for the town from whence it came. That quarry is long gone, but the name stuck. The real name is Verde Labrador.
Other quarries are unique. Sucuri is one. This one is a 'boulder' quarry. There are giant boulders way up in the mountains outside of Cachoeiro. They actually carve the blocks out of the boulders. One of these boulders can produce blocks for 4-8 months. Sonya Secchin, one of the owners, told me they had already located the next boulder and they are probably onto that one by now.
One thing that determines slab size is access. Some of the pictures depict relatively flat areas, so transportation of the blocks to the cutters is not too bad. But, the Sucuri quarry runs up a mountain on a snake-like road, so they have to be very careful about the size of the blocks they extract.
There are people searching for new materials day and night. Some are geologists and some are just old stone guys. This is a science, but it is science and experience combined. Most of the greens will come from a certain region, blues from another, exotics from another.
If the target of their sales is the United States, they will be looking for wilder materials. If they are targeting Europe or England, they will be looking for plain whites, grays, or consistent blacks. European tastes in stone are the exact reverse of those in the States.