Vintage Pretty and Delicate Louis Stern Pin/Brooch

Getting back into my jewelry collection and trying to segregate/identify everything.

This is a nice, delicate pin/brooch. Possibly real blue topaz in the middle but am unsure. 1/20 10K Gold Filled helps make it shine a bit more.

Marked - LOUIS STERN mark LSCO

LOUIS STERN CO., Providence, RI - est. 1871 - c. 1950 from this site: https://www.illusionjewels.com/research/costumejewelrymarkss.html Last record found in 1950.

Those who are more trained on the pins and clasps may be able to help date this is bit more closely. It looks closer to the 1940, max 1950 than prior to the turn of the century in my VERY novice opinion. Thoughts?