Now "et" (is that your real name?) you complain when I try and answer a question.

Spec analysis of the overall rock or structure in question would help analysis move closer to understanding the composition of such structures. If it were seen to be basaltic for example you'd probably reject the notion out of hand that it was a stromatolite - even if it looked like one at a macro level. You are not going to be able to see any small unicellular fossils in the first place with either visual or spec instrumentation, so I am not suggesting that you'd be able to separate a signal representing the fossils from that of the matrix they are embedded within -- unless the rock you are looking at is composed of a substantial amount of mineralized dead organisms in which case certain zones (bands) as are often found in stromatolites might give a different result that leads you to conclude that the band is possibly fossiliferous.