159 year old brooch patent.. special? - how?

I am fascinated by this patent from 1859. Patent #23042. When I first saw the drawing, it didn't strike me as particularly unusual, other than that is is a very old patent. A very nice pin with a design of a mother and children. But as I started to read the description I was amazed! This patent is for a photographic brooch! With the photograph made directly onto the glass front of the brooch! As an amateur photographer and joolie, my interest was piqued!

The patent describes enthusiastically that "a peculiar and beautiful effect is produced by placing a photographic picture upon the concave surface and the appearance of the finest enamel painting is readily imitated"

The process to make the brooch is described as using a watch crystal, which is held in the camera. ...the production of a permanent photographic or sun picture by causing the picture to be taken on a collodion film..on the surface of the glass. When the picture is finished, the concavity is filled with cement composed of gum shellac, resin and coal tar.

Pretty cool, considering that the National Geographic's website page about the history of photography says that the first permanent image was made in 1826 and the first photo of a person was made in 1839!