If you are a purist, you can think of a pyrrhotite crystal as an assemblage of two minerals, but most minerologists treat it as one. Thirdly, pyrrhotite is magnetic or at least weakly so. It is the next most common magnetic mineral to magnetite. Although not all specimens will show great evidence of magnetism if any, some will attract a paperclip or needle suspended from a string or move the needle of a compass. Good crystals are rare and should rightly be treasured as comming from a very unusual mineral.
Color is bronze.
Luster is metallic. Transparency crystals are opaque. Best Field Indicators magnetism, crystal habit, hardness and color.