This necklace is made an opal pendant and with 100% US-grade gold-filled materials. This means you can shower, swim and live in this without worrying about it tarnishing as quickly as typical "boutique quality" jewelry. US-Grade Gold-Filled Jewelry is at least 5% gold BY LAW. Gold-Plated jewelry can be as low as .005% gold. Gold-Filled is the next best thing, after solid gold, and at a fraction of the price!