Vintage Mexican Sterling silver abalone necklace

This is a vintage sterling silver Cabochon set Abalone shell Pendant. It is Stamped 925 Mexico. The Necklace is 20” long and stamped Italy 925, FGS, And VIOR, and the Pendant is 2&2/8” Long by 1” Wide. The abalone shell is 1.5” Long and the Necklace & Pendant is approximately 45.2 Grams. My Father purchased this beautiful vintage pendant in Mexico in or around the 50’s. He purchased the signed necklace in Italy.