What is a karat, and how does it affect price a ct gold buyer will pay? The amount that you will be paid by used gold buyers depends on the weight and quality of the scrap gold that you sell them. Karat is a measure of gold quality. Pure gold is 24 karat, and may be marked 24k. Other common stamps include 18k, 14k, and 10k, indicating a diminishing amount of gold. You may need a magnifying glass to read it, but most gold objects are stamped with one of these numbers.