The clasp is its own component. A skilled jeweler can remove and replace a double latch clasp without taking apart the rest of the jewelry, keeping the security function serviceable over time.
Visually Speaking
Sized wrong, a box clasp makes itself visible in the wrong way. If it's too wide, it interrupts a delicate necklace, and if it's too narrow and it reads as an afterthought on a substantial bracelet. Getting the proportion right is what makes the clasp merge gracefully into the piece.
Stone Story
Lab-grown emeralds share the same chemical composition and crystal structure as natural ones. What distinguishes them is inclusion type and growth pattern, not any difference in optical or physical properties.