Greek Coin - Porosity...

Sometimes, it is hard to tell the difference between porosity (genuine), and casting bubbles (fake) on a computer screen.

You need to examine the indents with a high powered loupe, to determine the shape of the indents. Casting bubbles tend to be much more regular and round, and corrosion (one of the reasons for porosity) tend to be highly irregular in shape.

Style and fabric as seen on the screen, suggest that this coin is genuine.

Hello!
I was curious about the causes of porosity. Could it be seawater?
Thank you very much, dear friends.
I always learn a lot from you!

Porosity occurs when the temprature is wrong when the silver is cast resulting in airbubbles within the material. This is why its often seen on counterfeit cast coins.

Pressumably even in struck coins the silver would have been melted to produce the blank so its not imposible to have porosity even on a struck coin.

When a coin is buried for a long period there can be a particle exchange like electrolisis between the coin and the soil resulting in pitting on the coin... easily mistaken for porosity.

Porosity can be natural corrosion to a genuine coin, and porosity can be evidence of casting bubbles.

What is important is to closely examine under high power magnification, the pattern and shape of the indvididual porosity holes.