I
still like it the way it is. Silver
denarii can be almost any color depending on the soil they are found in and the amount of copper in the
alloy. It is hard to tell from the photo, but another concern would be if it is a grey
patina it could be silver chloride (horn silver), and cleaning could remove much of the detail and leave a
pitted surface. Here is a copy of a photo I submitted a while ago of silver coins from
Caesarea Maritima. All are
good silver and I have chosen to leave most of them
as is.
https://www.forumancientcoins.com/board/index.php?topic=86391.25Hi, all. Here are some
denarii from
Caesarea Maritima to show the variety of surfaces that can occur with silver coins in a moist seaside environment. All are as found with the exception of the
Hadrian, which was even more coated in green than the Pius. This was cleaned about 40 years ago, probably with household ammonia, which as I mentioned can be risky if the silver has a high copper content. Ammonia dissolves copper and can leave a shiny surface that may be porous or brittle in the worst cases. I was lucky with the
Hadrian and I think it looks very nice, but I have left the others as they are.
(click on pic for higher
res.)