In the jewelry world, "gold vermeil," "gold filled," and "gold plated" refer to gold-coated pieces with varying thickness and durability. Gold vermeil involves a base metal (like sterling silver) covered with a minimum 2.5-micron layer of at least 10 karat gold. Gold filled jewelry uses a mechanical bonding process to affix a thicker layer of gold (at least 5% of the total weight) onto a base metal like brass, offering enhanced durability. In contrast, gold plated jewelry has a thinner gold layer (0.05% to 0.5% of the weight), making it more affordable but less durable. Understanding these differences helps in choosing jewelry that matches style, budget, and longevity needs.