Webster-Addie ultramafic body, NC - chromite and chlorite in dunite.

Click on the image to enlarge.           Photo: Dan Snyder

A chromite grain (solid black) in the process of altering to chlorite (gray and gray-brown blades). Surrounding (colored) grains are olivine. Chromite is a ubiquitous accessory in most peridotites of the southern Appalachians. The chlorite mineral is kammererite, a chlorite variety unusually rich in chromium and magnesium. Thus, it grows at the expense of both chromite (FeCr2O4), from which it takes chromium, and olivine, from which it takes magnesium and silica. Webster-Addie ultramafic body, Blue Ridge Mountains, Jackson County, western North Carolina. XPL. Imaged area 1.3 mm x 2 mm.