Carat

The carat (ct) is a unit of mass equal to 200 mg, which is used for measuring gemstones and pearls. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterwards in many countries around the world. The carat is divisible into 100 points of 2 mg.

Other subdivisions, and slightly different mass values, have been used in the past in different locations.

Back to Buying & Care →

Source: Wikipedia · Image: Wikimedia Commons · CC BY-SA 4.0

JEWELRYSTORM

Jewelry, demystified — how to choose, size, and care for rings, gemstones, gold and pearls, plus birthstones, metals, and the tools that make it easy.

Get new guides by emailOccasional emails. No spam. Unsubscribe anytime.

InformationAbout Contact Privacy Policy Terms of Service Disclaimer Affiliate Disclosure Cookie Policy

Every species, image, fact, and figure is drawn from Wikipedia and Wikimedia Commons, used under public-domain and Creative Commons licenses. No content is AI-generated.