These are two images of the same symplectite that formed in an Appalachian amphibolite. In the transmitted light image, the symplectite minerals are too small and indistinct for their visual identification. In the BSE image all the grain boundaries are sharp and individual grains well defined.  It is an easy task to put the electron beam on any of these grains and to not only identify the minerals, but also determine their chemical compositon.