The phrase "you could have knocked me over with a feather" means that you were very surprised. A person who is so surprised that they are a bit disoriented might feel like something as light as a feather could be enough to knock them over.
you are exited
If by "after time" you mean once the diamond is on your hand, the only way that a feather can be formed is if there is a catalyst to the occurrence ... by this I mean, for example, if a diamond was hit or damaged it could act as a catalyst to an interior feather spreading inside of the stone.
Maybe it's not air, it could be an ingrown feather or it could be a tumour?
The term "plucking a finch" is an outdated term referring to sex. Your passage really needs to be considered with the context to be sure but, plucking a finch to leave no feather could mean that the person has sex with a lot of people.
The expression is usually, "You could have knocked me over with a feather!" It means, I was so surprised (and distracted or disabled) that I could have been easily knocked over with a feather. In other words, my defenses were way down, or non-existant so almost anything could have knocked me down.
that your very happy
"feather in the wind" - can you say that in English? And what does it mean?
It would mean that you put a feather into a cup. Perhaps you mean "a feather in your cap," which was a way of showing an achievement and has come to mean any achievement.
Sending a black feather can mean a great many things. Sometimes sending someone a black feather can mean wishing death on them.
If you mean Hetty Feather by Jacqueline Wilson, Hetty Feather does not meat him.
A crow has lost a feather.
It mean's it has a zip or lost a zip, The zip is the line in the middle of the feather. UnZipped mean's it has no line in the middle, Look we have found a rare UnZipped feather.