Platinum over Sterling Silver BLUE SAPPHIRE Stud EarringsBlue Sapphire Stud Earrings They are Made with . 925 Sterling Silver The Blue Sapphire Stones are all 4 Prong Set Each Stone are Oval Shaped 5x3mm and Faceted Stones The Approx. Total Stone Weight is . 550 cts, That's . 275 cts Per Earring The Approx. Total Product Weight is 1 gms These Sapphire Gemstones Have Been Mined in Kanchanaburi, Thailand The Colors of Kanchanaburi Blue Sapphire are Usually a Deep Rich Inky Blue These Stud Earrings are Perfect