From the early 1900s we have a photograph of a nice looking lady with quite a collar! The dress looks to be black or dark fabric of some kind, possibly silk or wool gaberdine for example, and my guess is that the collar coordinated in color. It was probably very striking in person. Also interesting to note is that it looks like she was sitting next to someone, to the left of frame. This might have been prepared as an individual portrait after the couple’s original sitting.
The photographer was Gray, at 1030 Tremont Street, Boston, MA.