How do diamond carat weight and gold karat purity describe different things?
Last reviewed:
Direct answer
Carat measures gemstone weight, while karat describes gold purity; the similar words refer to different properties.
One metric carat equals 0.2 grams. Gold described as 18K contains 18 parts gold out of 24, not a gemstone weighing 18 carats. Ask the invoice to separate stone weight, metal weight and purity so the figures cannot be confused. A large stone need not sit in high-purity gold, and a high-karat setting says nothing about a stone's identity, quality or value.
Sources used
GIA 4Cs: Carat Weight
Gemological Institute of America
Metric carat weight, its distinction from gold karat, and the limits of weight-only comparisons.Source checked:
View sourceGuide to White, Yellow, and Rose Gold Engagement Rings
Gemological Institute of America
Explains karat and fineness. No live metal price, investment return or local hallmarking law is inferred.Source checked:
View source