A carat is a unit of weight used to measure diamonds and other precious stones , and is also used for gold . However, it does not refer to its weight, but rather to its purity.

One carat is equal to 200 milligrams. Pure gold is represented by 24 karats , however, it is very difficult to find gold pieces with this karat. This is because gold is a very malleable material, and if manufactured at its purest, it would be very fragile and easily deformed .

To maintain the shape of the piece, an alloy is used to make the gold harder. The most commonly used metals in gold alloys are silver, copper, and palladium.

The alloy is what guarantees the technical characteristics required for the execution of a piece, such as hardness and color. The 24-karat gold content corresponds to the 24 parts of the piece composed of gold. For example, a 16-karat gold piece means that 16 parts of the piece are gold and the remaining 8 parts are composed of another metal.

There are three types of diamonds:

– Yellow Gold : The additional elements are copper and silver.

– White Gold : in addition to yellow gold, it also contains so-called “white” metals, referring to silver, palladium or nickel.

– Red Gold : yellow gold in conjunction with copper, silver and zinc.

This rule applies to any and all gold pieces. The more karats, the more valuable and expensive it is , and the more durable it will be in maintaining its original shine and color.

Gold jewelry pieces feature contrasts of:

• 19.2kt (carats) or 800‰ (thousandths) - composed of at least 80% gold, with the remainder being made up of other metals in the alloy. This fineness corresponds to what is known as “Portuguese Gold”.
• 18kt (carats) or 750‰ (thousandths) - consisting of at least 75% gold, with the remainder being made up of other metals that make up the alloy.
• 14kt (carats) or 585‰ (thousandths) - consisting of at least 58.5% gold, with the remainder being made up of other metals that make up the alloy.
• 9kt (carats) or 375‰ (thousandths) - consisting of at least 37.5% gold, with the remainder corresponding to other metals that make up the alloy.

Gold bars correspond to 24kt (karat) or 999‰ (thousandths) gold, that is, gold not alloyed with other metals.

Less common, but also permitted under Portuguese law, is 22kt (carat) or 916‰ gold, which corresponds to a minimum of 91.6% gold, with the remainder being other metals constituting the alloy.