Twinkle Black Stud Earring. The Jet stud: a jewelry staple. Finely made with crystals with Jet Black color. This lovely pair of crystal Stud Earrings will add glamour and sparkle to evening and day wear. Classic style and bright color come together in these stud earrings featuring Jet Black crystals. Black, crystal, Stud, Butterfly, Copper, Not Handmade, Polished.