In most cases, they are from tribes such as Navajo, Zuni, Hopi, etc. We name an item "sterling" if it is tested to be at least coin (90%) silver.For silver, 90 - 100% purity: (silver acid) dark red (18K gold acid) white. 80 - 90% purity: (silver acid) light red (18K gold acid) blueish white. No return on international sales unless item is completely misrepresented. Please check out my other items. This item is in the category "Collectibles\Cultures & Ethnicities\Native American: US\1935-Now\Jewelry". The seller is "sixteenthalley-vintage" and is located in this country: US. 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, Sweden, Korea, South, Indonesia, Taiwan, South Africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain, Croatia, Republic of, Malaysia, Chile, Colombia, Costa Rica, Antigua and Barbuda, Aruba, Belize, Dominica, Grenada, Saint Kitts-Nevis, Saint Lucia, Montserrat, Turks and Caicos Islands, Barbados, Bangladesh, Bermuda, Brunei Darussalam, Bolivia, Egypt, French Guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman Islands, Liechtenstein, Sri Lanka, Luxembourg, Monaco, Macau, Martinique, Maldives, Nicaragua, Oman, Pakistan, Paraguay, Reunion, Uruguay.