Originally Posted by
Steel
Due to how Novaculite cuts, this is not as easy of a question as it first seems. One place will rank the black as finer as the translucent and another vendor will say the translucent is the finest. With the different levels of burnishing individual people will fight "tooth and nail" one way or another based on their particular stones. This makes everything very confusing. In reality they are grouped more on Specific Gravity and how close the particles are instead of how fine the size of the particle is or grit rating. Some time with the search button will explain all of that better. Then there is the issue of how it is prepped. A translucent that is well burnished can finish finer than a black that is not burnished and vice versa.
With all of that being said, they are supposed to be around the same specific gravity and in the same category so I think you will find most of the difference in how the stone is prepped.