I cannot identify the maker of this mark. It consists of the initials "JM" below a line and two stars above that line in a diamond shape. There are also two column-like supports on either side of the monogram which connect to the line. It makes it look like the cross-section of something. Anyways, the bar, two stars, and J.M. are identifiable but the other shapes on either side aren't clear to me.
I found a few mentions to the JM mark in France on the forum but all posts had broken images, so I wasn't sure if this was explained before or not.
Hello Your object was made by Joseph Alexandre Martel, a manufacturing silversmith, working in Paris at 41 rue Beaubourg. He registered his mark twice, on 8 July and 20 October 1888, erased on 30 April 1914. His mark was initials JM, two hammers (deux marteaux) with 2 stars above. The hammers are a mnemonic device for his name, Martel/marteau.
See the French Ministry of Culture website for Paris marks registered after 1878.