So I got some powdered sulfur to experiment with some junk silver coins. One of these experiments consisted on baking a coin in this sulfur just to see what would happen. Well, what resulted was a black, crusty mess with few defining characteristics. Thinking that this black crusty stuff was just some caked-on silver, I hammered the coin until the crusty stuff came off so it could be a discernable silver coin again. What I saw shocked me. Here was the coin before my experiments: Here is the result. The above coin is on the right. The left coin was another, similar experiment, just not as severe of a result. The coin weighed nearly 4 grams less than it did before! I then started looking at the crust fragments to see what was there to see. On this piece, there are two clear layers. The outermost layer is most likely caked-on sulfur, but the inner one is most likely the coin itself! The inner layer measures about half a millimeter thick, which would explain the drastic weight loss. I found it surprising that the sulfur was able to seep so deep into the coin and react with the silver. So remember, when you are buying a toned coin, you are just buying a coin with a thin layer of crusty corrosion.