Figure 30. Photomicrographs of a doubly polished thin section of sample 796-48,277, a low-grade ore consisting of alkali amphibole (mga), monazite (m), and magnetite (mt), as well as relict grains of the limestone marble host rock. The alkali amphiboles contain inclusions of monazite. Monazite and alkali amphiboles are replaced and cut by fresh magnetite. A, Transmitted light; B, Reflected light.
This page is https://pubs.usgs.gov/bulletin/b2143/fig30.html
Maintained by John Watson
Last updated 01.26.98