In the past, the use of the term carat was limited to the measure of weight. Over time, the unit of carat developed into two diverse terms or variants.

On the one hand to measure the weight of gemstones.

  • CARAT As a measure of weight for gemstones.
    1-Carat weigh’s 0.2 gram so 1 gram is 5ct.
    The biggest diamond ever found was the so-called “Cullinan”. As a rough stone, its weight was 3106 ct or 621.2 grams.

On the other hand as the proportion of Gold contained in an alloy.

  • KARAT The unity that represents the fineness of gold.
    – 24 Karat or 999.99 is fine gold.
    Gold bullion bars up to 1 kilo are made are made of fine gold.
    All other forms of gold are alloys.
    – 18 Karat or 750.
    Most of the hi-quality jewelry is made of 18-karat gold. In the case yellow gold, the alloy contains 75% pure gold 12.5% silver and 12.5% copper.
    – 14 Karat or 585.
    Lower in price, this is the preferred alloy for the US market and Germany. 58.5% are pure gold 41.5% are other metals.
    – 9 Karat or 375.
    only 37.5% is gold 62.5% are alloy metals.

Only starting with 18 karat, more than half of the surface of a piece of jewelry is actually gold! That is to say, that most of what you see in 14 or 9 karat is copper and silver.
Although 18 Karat is softer than 14 or 9 karat, surprisingly it is much tougher and durable.

Scratches in 14 karat abrade material from the surface.

In contrast, in 18 karat and higher alloys abrasion in reduced because the atoms on the surface of the gold are only moved. This is why 18 karat gold last’s much longer than gold with a lower content of gold

Carat has been updated to Karat

Karat (18K or 750)

Unit do indicate how much gold an alloy contains

Carat is used to weigh diamonds

Carat or (ct.)

unit for the weight of a gemstone