Great day and it might get even better. The gilt button is nice, but your other keeper in the post may be the plain button with the rim. Not being able to see that back I can't say for sure, but what it appears to be is an early to mid. 1700s French Colonial Marines button (Compagnies franches de la Marine) If you can't tell 100% by comparing the back of your button to the pics below post a close-up and i'll tell you one way or the other. Usually they are very dark out of the ground but maybe other factors can change that. I have a few near perfect examples.
PS.. Most found are missing the shank.
The Compagnies franches de la Marine, comprised of infantry under royal naval authority, formed the backbone of France's colonial military establishment in North America. While other French regular and colonial units served in the New World, no other forces served continuously or over such a vast territorial expanse. The classic button pattern worn by these troops from Canada to the Gulf of Mexico until the end of the French colonial period was a convex, rimmed, cast brass type exemplified by the specimens shown above. Until the 1730s, these buttons were made with integrally cast, slab-like shanks with drilled eyes similar to those in use by the Spanish military establishment at the time (upper left/Dauphine Island, Alabama). By the 1740s, the drilled eye form had been replaced by a similar form featuring a cast brass rimmed button body with an inverse staple-like copper or brass wire eye soldered or brazed to the button's back (upper right/Mobile, Alabama and Lake Champlain, New York).
http://www.artifacts.org/francepage.htm
