Petrographic scopes are a tool that separates the hobbyists from the pros. "Identifying" a mineral isnt the job we count on in the foield. We do confirmations by thin section and radiological analyses. In beginning geo the lab practicals are usually based on obvious rock groups. Telling quartz from pyrite is easy and rock hounds are better than geo students because the geo student may be wondering what is the exact species of quartz or pyrite and why is it there.
What the OP is doing is determining EXACTLY the mineralogical makeup that gives a big clue to the chemical "Thermometry" of how the rock body was emplaced and how deep and ofdten , when. You notice that he already knew that he had biotite and hornblende. He wanted a better clue as to their ID in a thin section not a hand specimen. Optical propeeties are a much more definitive way to determine chemical structure of the minerals thn hand specimens.
Beginning geology for non majors is usually done to fulfill a science requirement were not creating new prospectors. Majors are taught the whys and the details of understanding earth processes, not identifying minerals as an end point., they are taught to apply a whole bag of science tricks (and the theory behind em)
Id muh rather a kid know how to id a mineral with a pet scope than in a hnd specimen. Some minerals form these "PIzza mixtures of defetc crystal lattices so they show us an almost unique xhemical makeup from each location. So a minral like a plagioclase feldspar MUST be identified very precisely according to its pwrecentges of sodium to Calcium Silicates. They form what is known as a "SOLID SOLUTION" which, can hve a whole range of Na /Ca ratios (and each hs a unique name tht only is meaningful when analyzed as a whole rock under a pet scope under polaried light. The thermodynamics of emplacement are tightly tied to those ratios . This gos for hundreds of other minerals (even quartz, which has quite a few unique lattice based polymorphous forms that can only be analyzed by pet scope).
Each one is unique in understanding whether it was emplaced in a pegmatite or melted by a meteorite impct..