Looping through array to find a specific class?

I have an array of a class witch is called Block. The block class two variables: position(witch is a Vector3) and type(String). In my script I assign the position and type through a for loop. When I run the script it creates an array of 9 "Blocks". My next step is to make each Block of the array check if there are any blocks around it with the type of "dirt", but after an hour of trying I ended up with nothing. Could anyone help be do this? I think I need a for loop that checks if a block is at a specific position and has a specific type.