Classic Chain 9.5 MM Silver Square Stud Earrings With Black Sapphire John Hardy Ladies Earrings. SKU: EBS961824BLS. Color: Silver-tone. Metal Type: Sterling Silver. Metal Stamp: 925-Sterling. Gem stone type: Sapphire. Earrings style: 1 Band. John Hardy Classic Chain 9.5 MM Silver Square Stud Earrings With Black Sapphire.