14kt gold is durable because its alloy metals make it measurably hard and scratch-resistant. A practical advantage if the piece will be worn, not stored.
Care & Keeping
If a clutch back gets lost later on, it's a straightforward replacement. Standardized fittings in matching precious metals are available at any jeweler, and the swap won't require altering the earring. This is a good thing to keep in mind when gifting stud or on-the-ear earrings.
The Perfect Gift
Cultured pearls are the traditional 30th wedding anniversary gift. They also carry symbolic associations with purity, wisdom, and enduring love across cultures. That's a lot of meaning for one gemstone to hold, but it does it beautifully.