Stone Arrow heads

[junker]

Hi,
did we have a thread about stone arrow heads already ?
I got these here in germany, but the seller says, that they might come from the US.
One is a lance head i guess, this is about 11 cm.
They are of differnet stone material, from red to tigerstriped yellow and black.
Maybe someone has a good link for me how to decide if it is an old one or a recent made one.
Thanks

Dirk