The Problem Just sent two suspect (below) 'desert patina' Roman Empire bronzes to NGC in Sarasota. I know there are already quite a few CT threads about dealers adding desert patina, and from what I understand it can be difficult to tell real sand from fake. Is there a strategy for identifying repatination by texture etc with a loop? Since we ofc clean ancients, there seems to be a continued battle on where exactly to draw the line on what is ok... Some people even consider repatination acceptable: http://www.fontanillecoins.com/tooling.htm NGC's Seemingly Relaxed View on Repatination Grading can be a little cost prohibitive and most ancients aren't slabbed, so among the threads about desert/sand patina I haven't seen a lot of talk about NGC's stance on the issue. I trust that David Vagi and his team at NGC Ancients know their stuff. I sent the below two coins with standard service to get NGC's full view. This ensures I get that italicized comment in the bottom right corner of the slab label... It seems sandy coins either either get "Sand Patina" or "repatinated" as a comment. Either the patina is real or fake. Sand Patina Example: https://www.ngccoin.com/certlookup/4094567-003/61/ Repatinated Example: https://www.ngccoin.com/certlookup/2490527-002/61/ What is interesting is that NGC will still slab repatinated coins, thus taking the view that repatinating to accentuate devices is ok? If a coin was tooled or otherwise altered improperly, it would not be allowed in an NGC slab. This also creates a loophole, assuming repatination is bad: a repatinated coin could be sent in via NGC Ancients Economy service and be slabbed without any notes on repatination as comments are not included in economy service. The coin could thus be sold as a coin with genuine patina, when in fact it has been added: (Not sure whether this coin has real patina or repatination): https://www.ngccoin.com/certlookup/2070690-002/61/ Next Steps If either of the two I sent come back as repatinated I may send them into NCS or exploring water/acetone etc. Not going to disclose where I bought these to avoid the thread becoming a dealer roast. I didn't pay a premium for these coins -- just trying to learn more about what to look for. Thanks everyone!