(Thank you!).

Roy – an overall uniform discoloration is probably due to toning. The silver will chemically react with sulfur in the air and form a tarnish. An overall uniform tarnish is not due to oil from your finger – a localized discoloration and maybe a print is due to an oil film. An attractive tone can be worth more than an untoned coin based on appearance. Based on your condition grading, you would consider your coin to be a nicely uniform toned MS50. This indicates that the coin was worn and then toned – which is probably your case because of many years in your family’s possession without any additional circulation.

Bruce – titanium forms an oxide or nitride layer when exposed to high temperatures and air. The unprotected exposed area loses its ductility and will lead to a premature failure when exposed to stress. The surface contamination (alpha case) is avoided by using an inert gas or vacuum environment when heated. Titanium mill products are sold with the alpha case removed. NB – the titanium surface oxide is self-passivating as opposed to ferrous metals which can oxidize through the entire section.

Gotta put them in air tights discs. That cardboard is not air tight. Sometimes the plastic sticks harder to one side and you get one side toned.