Sending bitcoins to private key

[gsingh]

I have been playing with bitcoin keys.

Pasted this private key in blockchain and it appeared just as public key.

https://blockchain.info/address/5JM4ACqJovsTTVUDTy8hNYFJ7ENvHG7G62AHcqKVAwpggTtXcxC

What happens if someone sends some bitcoins to this(private) address. This can happen accidentally.

I was expecting an alert from blockchain telling me that this is a private key not public address. Can I differentiate private and public address by naked eye?

[Rannasha]

Public addresses (note: not the same as public keys), start with 1 or 3. Private keys start with 5, L or K.

[gsingh]

That helps, thanks for clarification.

I meant public address, never heard any public keys concept though?