Carat Measurement – Gemstones

Carat is a measurement of mass we use for diamonds and other precious gemstones. The word Carat derives from French, Italian & Arabic, it translates to the word bean-pod – specifically the carob bean.

Throughout early history, carob seeds were used as a comparative measurement to determine the mass of a gemstone. It was believed there was little variance in the seed size, therefore they were considered a perfect object for measurement.

It wasn’t until 1907 that the ‘carat’ was officially adopted as a unit of measurement. Today carat weight has been globally standardised, with 100 carats equating to 20 grams. The carat remains a universal form of measurement for the mass of a gemstone.  It is important to note that the carat weight of a stone does not necessarily determine the surface size of a stone. Gemstones with similar size face measurements can vary in their depth and weight. It is always best to view a gemstones surface dimensions when understanding what your stone might look like.

Carat Measurement – Gold

The carat measurement in regards to gold refers to the percentage of pure gold mixed together with alloy metal.  As gold in its pure form is incredibly soft, it is alloyed with other metals to generate hardness.  Gold carat is a measurement out of 24 – with 24 being pure gold.  Therefore, 9ct yellow gold is 9 out of 24 parts pure gold.

While we now understand carat gold as an indication of percentage of gold in a piece, the origins of this measurement came from the early usage of carat weight.

The medieval coin known as a the Mark had a carat weight of 24. To create these coins, pure gold was alloyed with other metals to help hold their shape. The purity of gold in each coin was then expressed through the carat weight of gold present in each coin.

Pictured below, coin dated 42BC, Northern Greece.

If you would like more information about gemstones or gold, visit our materials page.  For all other inquiries reach out –  We are happy to discuss any questions you may have.