silver sulfide. its an oxidation process.
For copper or some copper alloys coins the coating is hydrated copper carbonate.
I think to resistance to corrosoin.
If it can be written :- as or As then it is a roman coin. If it is always written As (even in mid sentence) it is the chemical symbol for Arsenic.
Yes, Clorox bleach can erode a coin because it is a strong chemical that can react with the metal in the coin, causing it to corrode or deteriorate. It is not recommended to use bleach on coins as it can damage their value and appearance.
The term for a coin that sounds like an odor or smell is a "scented coin." Scented coins are specially treated with a coating or infused with a fragrance to give off a specific smell. These coins are often used for commemorative purposes or as collectibles, adding a sensory element to numismatics.
The black coating on an old coin is typically referred to as patina, which is a thin layer of oxidation that forms on the surface of metal over time. It can consist of various compounds depending on the metal composition of the coin, such as copper sulfides or oxides.
For copper or some copper alloys coins the coating is hydrated copper carbonate.
The price of the coin depends on its condition here a link to a website so you can get an idea of what the coin on average sells for. http://listado.mercadolibre.com.mx/un-centavo-1890-mo.-republica-mexicana
The melting of a coin due to heat is a physical change as it alters the physical state of the coin from solid to liquid without changing its chemical composition. The black color that appears is likely due to the formation of an oxide layer on the surface of the coin, also a physical change.
7-24-11>>> Assuming the coin is circulated and has no mintmarks, retail value is $38.00-$41.00 depending on how much wear the coin shows. The 1890 Morgan is a common date.
Need to know the country and face value of the coin - and condition.
Assuming the coin is circulated and still in collectible condition, the 1890 Morgan is a common coin, current average values are $38.00-$44.00 depending on the grade of the coin.
Anonymous
A seated Lady Liberty.
It's an image of Liberty.
Assuming the coin is circulated and has no mintmarks, retail value is $23.00-$31.00 depending on how much wear the coin shows. The 1890 Morgan is a common date.
Assuming the coin is circulated and has no mintmarks, retail value is $23.00-$31.00 depending on how much wear the coin shows. The 1890 Morgan is a common date.