Sulfur mustard. Sulfur mustard, commonly known as mustard gas, is the prototypical substance of the sulfur-based family of cytotoxic and vesicant chemical warfare agents known as the sulfur mustards which have the ability to form large blisters on exposed skin and in the lungs.
Silver jewelry, ornaments, and silverware are traditionally made from Sterling Silver. Sterling Silver is an alloy composed of 92.5% silver and the remainder 7.5% other metals, usually copper. Britannia Silver - Silver that is alloyed with a maximum of 5% other metals.
My guess is that it was made from a silver covering with copper in the middle so it would not be 90% silver but some smaller percentage and that it did not use a nickel face. If that is true then I think I have a really rare coin indeed. Of course I could be just hearing things and it is a normal quarter. Dec 7, 2010.