Creating Gemsone Diamond materials

Hello,

I have searched the Substance 3D Designer form but [perhaps secondary to my less than stellar search skills - and thus if this is a redundant topic post I apologize. ] I have not been able to find a discussion on creating gemstone, diamond, pearl and precious metal materials. Thus, if one [ or more disscussions,; perhaps topic specific, already exists, could you please kindly  direct me as to where this discussion [s] reside. Thank you. Appreciated.

If, if my chance, however, one [ some of these disscussion topics]  do not already exist, then perhaps this is an opportunity to start one [ given interest in thesesmatter].

Thank you,

Andrew

p.s. I have found some pretty applicable already made materials but the goal is to be ale to create one's own materials based on quite exacting and specific ways that the resultant materials would be used.