Grimstone progression block off

The new grimstone layer should require a higher level tool than just wood to access because of the higher concentration of ores I think it would be cool if you needed a diamond pick to break grimstone and there would be a sheet of it at y=0 making it kind of like a first layer of bedrock that you have to be a higher level yo get below leading to a better skill tree and maybe there could even be an exclusive ore down there.