Bubble Texture in Grey Art Glass Stud Earrings in Grey from Costa RicaInspired by the 'thousands of designs' possible with glass, Costa Rican artisan Ileana Umaa creates a unique pair of stud earrings. She crafts each round earring of clear glass, detailed with small and intricate air bubbles with a grey pigment. materials: Glass, stainless steel posts Post earrings High polish finish Hand crafted item color, size and or motif may vary slightly 0. 2 in. H x 0. 4 in. Diam.