These remind me of Venetian glass. Swirls of browns, beiges & creams cascade & twirl through clear lucite. They were drawn into canes & then sliced ala' Italian Lampwork Glass style. Each measures about 8mm in diameter: the perfect tiny size, classic & classy.
Most all earrings are made with vintage lucite parts that were made in the US in the 1960's - early 80's. I hand-set them with surgical steel earring posts and they have sturdy surgical steel/acrylic backings on them as well. Light-weight & fun to wear.