I've always wondered what the source of black spots or streaks on some gold MS coins are. Could people who are more informed chime in on various sources of problems on MS coins? What exactly are bagmarks and how are they caused? For example - this is a coin graded MS63 by NGC, and the spots don't look like wear or any sort of copper toning to me, and most don't seem like bag marks (at least the way I understand them) It really only pops up in certain lighting conditions as well, I didn't see these many marks in the shop where I bought it a few years back. Here's another coin where I've observed it - this Russian 10 rouble is more like an XF/AU coin I guess, and the strike is actually quite nice, but the spot on the head and cheek is a major detractor to the beauty. Seems a bit unusual to have such concentrated wear on one location
There's probably a thread or two on this, but I just read Roger Burdette's fantastic book on Saint-Gaudens Double Eagles and he had some of the latest information and a few pages on this with regard to Saints and bullion coins. I'll retrieve it later when I get home if the answers here aren't covered in his book.
They look like bag/handling marks to me. Since gold is the softest coining metal, gold coins mark very easily.
That's what they are, simply contact marks. The black color is a trick of the light really, same kind of thing happens to silver coins as well. Contact marks, light abrasions, they can sometimes appear to our eyes, or a camera, as being black in color because of the way the light is refracted and reflected.
Gold coins will photograph contact marks as black more than any other metal. Its weird, but must be a function of the metal's properties.
There is simply a little DIRT on the wear spot of the Russian coin. I need a better image of the $20 to make a comment.
Interesting. So these are primarily bagmarks on the 20? I thought there would be more visible chips on the surfaces and fields in that case.
The russian 10 rouble was bought mostly as a semi numismatic piece (partly for bullion value). Is there any safe way to get that dirt off without damaging the coin?
For beginners only and for gold coins only: Put it in a dish of soap & very hot water and let it soak. When the water is cool, pick it up by the edges and swish it around. Run it under hot running water and dry with a hair dryer.
