I cant find any sterling silver markings, but I read this on line about unmarked pieces. I think it is nickel silver and pewter with turquoise. The Baja centerpiece is 2 1/8 wide and about 2 1/2 tall.
It is lovely and very impressive to wear! The item "Vintage Zuni Squash Blossom Necklace" is in sale since Wednesday, May 29, 2019. This item is in the category "Jewelry & Watches\Ethnic, Regional & Tribal\Native American\Necklaces & Pendants". The seller is "laurel*tree*studio*" and is located in Bardstown, Kentucky. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Iceland, Macao, Martinique, Reunion, Uruguay, Russian federation.