What makes a hinged piece look more finished than one with an external clasp is simple: when it's closed, the join is nearly seamless, and the design you actually see is the design as it was made to look.
Elemental Detail
For someone with sensitive ears, platinum and 18kt gold posts are the right specification. Their high precious metal content means minimal alloy exposure at the piercing, which is where nickel-related sensitivity most commonly manifests. It's the detail that turns a thoughtful choice into a wearable one.
Stone Story
To make lab-grown diamonds, High Pressure High Temperature applies extreme mechanical pressure and heat to a carbon source, replicating the physical conditions of geological diamond formation. The other method known as Chemical Vapor Disposition introduces carbon-rich gas into a vacuum chamber and deposits it atom by atom. Both create the same exact gemstone.