If you’ve ever walked into a jewelry store, chances are you’ve encountered the terms “karat” and “carat.” But what exactly is the difference between the two? This blog breaks it all down!
Karat vs. Carat Definitions:
Karat: A karat (abbreviated as K) is a measurement unit used to tell you how pure gold is in a metal mixture. The scale goes up to 24, where 24-karat is pure gold. From there, common karats you may see include “18k,” which equals 75 percent gold, “14K,” which is 58.3 percent gold, and “10K,” which is 41.7 percent gold. In short, karat is the indicator that tells you the percentage of gold in your gold jewelry! (If you want to know more about why gold is mixed with other metals and which metals are used, read this Betz blog).
Carat: A carat (abbreviated as c, ct, or ctw for carat total weight) is a standard unit of weight to measure gemstones and diamonds. A carat equals exactly 200 milligrams (.2 grams). It is important to note that when measuring carats, the relevant factor is weight, not overall physical size! Many customers come in referring to diamonds as “carat size,” when in fact, two 3-carat diamonds side by side, for example, may look noticeably different in size/measurements.
History:
This is where two worlds (or words, if you will) collide! Both Karat and Carat originate from the unit of measure in the Mediterranean known as the carob tree. The carob tree produces pods that have seeds inside; those seeds are very consistently the same weight, 0.18-.20 grams. Since ancient Mediterranean traders did not have scales that automatically calibrated, they would use the carob seeds to offset weight on one side of their scales. Thus, it became a way to compare and measure small units of weight such as gold and gemstones. The distinction between K and C spelling really gained traction in the 1800s as British and American jewelers began to spell them in different ways consistently (Karat for weighing gold, and Carat for stones) and it became the global standard.
Fun Fact:
During the Roman Empire, a new currency was introduced; solidus, which became the dominant currency. This is relevant because the solidus was divisible into 24 smaller units called siliqua. Each siliqua weighed approximately one carob seed. From here, 24 became the prevailing way to determine gold purity (or solid gold) where 24 out of 24 pieces was a piece of solid gold!
We hope this gives you a bit more confidence when shopping for fine jewelry, but at a minimum you are better prepared for the next trivia night!