This is a large unidentified fossil leaf from the Fort Union Formation of Montana. It is from the Paleocene, or approximately 60 million years old. The dark orange preservation contrasts well against the lighter shale, and all the veins of the leaf can be seen in good relief. There are some touchups to the outer edge of the leaf where some of it flaked onto the negative during collection as well as a repaired crack through the center fo the leaf.
The color of the rock and the leaf are rather unusual and different than most of the leaves seen from the Fort Union Formation. They were collected from a locality where a fire in a nearby coal seam "cooked" the rock at sometime in the past. This changed the color and gave it a chalky texture.
It comes with an acrylic display stand.