This coin frame set has proven quite popular, and I've constructed several different versions. Examples of different materials are shown here.
This one was constructed in red oak, while the finish is Minwax Polyshades Bombay Mohagany.
This one was constructed in bloodwood with maple inserts, with a clear finish. The quarters are retained by clear acrylic windows.
This one was constructed in pine, while the finish is Minwax Polyshades Bombay Mohagany.