The gems on Roshar, are they the same as the gems you and me know, or are they a byproduct of Investiture?
For the most part they are the same as the gems we know, which will ask the question, "Since most of them are chemically identical, other than color, what differentiates them?" and in the cosmere, color is very important, so I'll just leave you at that, but most of them are going to be gems like we have. If you took a ruby from our world to Roshar, it could be Invested by the highstorm.
We will RAFO that for now.