Is there a test to determine if a nail is galvanized or not?
Those are galvanized. The texture says it all.  Those different dark and light spots of silver all over the nail are crystals created as the zinc quickly cools in the air. Take a look at the image below and at this article by the American Galvanizer Association.

https://www.google.com/url?sa=t&amp;source=web&amp;rct=j&amp;url=https://galvanizeit.org/uploads/publications/Galvanized_Coating_Appearance.pdf&amp;ved=2ahUKEwi4xsy_45vpAhXDZs0KHfSXAmcQFjADegQIBxAB&amp;usg=AOvVaw0wgwaqYYgCGJSuVaKVa8is&amp;cshid=1588649225545