i believe the insignia is for a women's branch of the moose lodge. this type of pendant--rectangular or oval with an ornate stamped filigree frame supporting some kind of insert--was popular from around the 20s up through the 40s and made in all materials from platinum down to base metal. this looks like a 30s costume jewelry example with mother of pearl and probably gold filled. the most valuable ones, as far as the costume jewelry type goes, are sterling with frosted glass inserts. the GF ones are worth less, and ones with organizational/fraternal insignia are worth less than ones that simply have a decorative motif because they have less of a wearability/fashion factor.
see ebay listing
Antique Notre Dame University Ladies Pendant w Filigree on Mother of Pearl | eBay for a similar example
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