I use a variety of materials when creating pieces - gemstones, crystals, vintage glass, bone and wood.
All earrings are finished with either Sterling Silver, gold-filled or niobium ear wires, all of which are hypoallergenic for those with sensitivities. All metal and chain used is nickel-free.
Some metals (particularly Sterling Silver and silver plated) will tarnish over time - it’s natural. Shine them up with a soft cloth (preferably, a jewelry polishing cloth) and they’re good as new.