Epidote, pyrite, and titanite in greenschist.

Click on image to enlarge.          Photo © Daniel R. Snyder

Epidote (high-birefringence, high-relief mineral, at right), pyrite (opaque mineral grains at left), and titanite (brown mineral surrounding pyrite). Greenschist,  specimen No. 1. Pebble in glacial gravel, southeastern Michigan. Provenance likely northern Ontario. XPL above, PPL below. Imaged area 1.3mm by 2mm.

Click on image to enlarge.          Photo © Daniel R. Snyder

Metagabbro with sericite and titanite

Click on image to enlarge.          Photo © Daniel R. Snyder

Diorite-gabbro altered to metagabbro. A grain of feldspar has been largely altered to sericite (large mass of fine-grained gray-brown material in center). Two green hornblende grains are at top center and right center. A brown grain of titanite is at bottom right, Mt. Prospect complex, Bantam, Connecticut. XPL. Imaged area 1.3mm x 2 mm.