Back-scattered electron image of the main aggregate of monazite-(Sm) and manganocolumbite (C) embedded in quartz (black). Variations in brightness of the monazite-(Sm) are controlled by the Th content, whereas the ratio Nb/Ta affects manganotantalite.
Location:
Annie Claim #3 pod, Greer Lake intrusion, Archean Bird River Subprovince of the Superior Province, Southeastern Manitoba, Canada.