Kokopelli sterling silver brooch pin opal lapis spiny oyster gemstones signed GS

Kokopelli sterling silver brooch with inlay gemstones which appear to be opal, lapis, spiny oyster. Please check all pictures for more details. This piece is signed GS which I believe is signature of Navajo artist Glenn Sandoval but not sure. It has some natural patina on the edges and on the back. Size: 1 3/4” x 1 1/4” Condition: used excellent