I know it is not a big thing to grade and slab ancients, but I have a question and will tag @Insider and @BadThad here also. The question is that the use of Renaissance Wax in not uncommon in ancient coins, and since this would show up as a surface contaminant, would this lead to such coins being non-slabable (sic).
you can contact NGC and ask them-- https://www.ngccoin.com/contact/ or tag Barry Murphy, he works at NGC
The place and the people to ask this would be directly to NGC. I've posted your question on their forum, and will let you know when I get an answer (it may be a while). I would suspect, however, that they would frown on the wax left on the coin.
Just out of curiosity, with or without a Renaissance Wax on a coin, what would you do if the coin that is slabbed develops bronze disease? (I just assumed the coin is made out of bronze based on the renaissance wax usage) And what is the advantage of slabbing of an ancient coin? They don't even guarantee the authenticity.
I think Renaissance Wax actually prevents bronzes to develop bronze disease or am I wrong in that? Assuming that the coin did not have any trace of bronze disease before slabbing I think it is very unlikely it develops bronze disease inside the slab especially if treated with Renaissance Wax. And as far as I know slabbing is just an American thing on increasing the value of the coin because it is graded by for example NGC (which does guarantee authenticity when slabbing if I am not wrong).
Reinassance Wax does not always prevent BD, and may in fact lead to BD by trapping moisture underneath. Your best bet against BD is to inspect your coins regularly and learn how to treat BD in case it ever pops up. Other than that, a treatment of verdicare may be more efficient than reinassance wax at preventing BD.
Debates on slabbing a coin have waged for as many years as they have been slabbed. Increasing the value as far as appearance is debatable, but for coins where it applies, the corroboration of authenticity is a plus. I think that there are other countries that have grading companies, but I might be mistaken (for the first time in my life ).
In one ear and out the other Dept. AFAIK From what I've read, NGC does not guarantee ancients. It may be different now that Barry is on staff. It is very important to find out the answer so hearsay such as what I posted does not get spread around if it is not true. Wax or any other coating on coins is not always detectable. I see no reason why an attractive an evenly lacquered coin should be "detailed" as long as "lacquered is on the label. I guess that's what's done now with "detail" grading. As for BD, in many cases, it is not visible at point-of-sale due to various things old-time collectors/dealers know. Unfortunately, even a careful exam using a stereo microscope will not always detect this "acceptable" alteration.
As @Sallent pointed out already it does not prevent BD. It can prevent only if the BD is totally cleaned from the coin and wax is applied properly. But it can be difficult to clean the BD completely. Since BD is an autocatalytic reaction, any trace amount of moisture or HCl left on the coin can trigger it. Best thing to do is to keep an eye on the coin. And NGC certainly does not guarantee the aucthenticity: "NGC Ancients will only grade coins that it believes to be genuine. Authenticity and attribution represent the opinion of NGC Ancients and are not guaranteed, nor is any guarantee implied. Please see the NGC Ancients Coin Grading Guarantee for complete information." Source: NGC Ancients
Concerning Ren-wax, we will encapsulate a coin that has been treated with Ren-wax, as long as it's properly applied. Cleaning and repatinating is not as big of an issue with ancient coins as it is with US and world coins, and we are therefore a bit more liberal in what we will and won't encapsulate. Nearly all silver has been cleaned and most bronzes get cleaned as well. Constantinian AE's don't come out the ground with nice glossy brown surfaces, and those nice "desert" patinas that perfectly highlight the devices didn't come out of the ground that way. We don't encapsulate bronzes that have been filled with putty, we don't encapsulate tooled coins and we don't encapsulate obviously fake desert patinas because you can't tell what's under the applied dirt. Concerning the NGC authenticity guarantee, I'm not going to rehash that for the 10th time. Search the archives and you can find plenty of comments by me on this subject. Barry Murphy
Cleaning shouldn't be a problem indeed as all the ancients (except the ones comes from very well preserved hoard)have to be cleaned before you can see what it is
Thanks for the reply. Out of curiousity, and for those less familiar with the process, what is the difference between "properly applied" and "improperly applied." Perhaps someone here can show pictures of coins with this?
If anyone is interested, p. 2 of this thread contains relevant comments: https://www.cointalk.com/threads/an...l-list-a-coin-condemned-by-sear.313342/page-2
