There’s a lot of jeweler’s jargon for gold — terms such as gold-plated, gold-filled, and solid gold can be confusing, even when you read the fine print. You might’ve also seen the word vermeil ...

In the past few years, a new crop of fine jewelry start-ups have popped up, shaking up an industry that can feel intimidating to outsiders, and demystifying the process of buying diamonds, gemstones, ...