A carat is a unit of weight used to measure gemstones and pearls. One carat is equivalent to 200 milligrams, which helps jewelers and buyers understand the size of a diamond or other precious stones. The more carats a gemstone has, the larger and often more valuable it is, but other factors like clarity and color also play a significant role in determining its worth. When shopping for jewelry, it's important to consider carats along with other qualities. For example, a 1-carat diamond may look different depending on its cut and clarity. Understanding carats can help you make informed choices when selecting beautiful pieces for yourself or as gifts.