Artisan Inga Enamel on Copper Brooch

A gorgeous work of art is this enamel on copper square brooch. The enamel is several layers deep alternating with gold and copper foils as well as green blue and white enamel. The work is signed Inga on the reverse side. The vintage and provenance is unknown. The dimensions are 1"x1" with a slightly convex surface. A pin for attachment is adhered to the back. The condition is excellent.