How to Calculate the Purity of Gold in Karat

Understanding Gold Purity and Caratage for Bangladeshi Jewelry Buyers

Gold is a cherished and timeless metal, adorning jewelry for centuries. In Bangladesh, where gold holds significant cultural and economic value, it's essential to comprehend the intricacies of gold purity and the caratage scale when purchasing jewelry. This knowledge ensures you make informed decisions when investing in these precious items.

Gold Alloys in Bangladeshi Jewelry:

In Bangladesh, jewelers often use gold alloys to enhance the durability and strength of gold jewelry. The two most common types are:

  1. Yellow Gold: Made by mixing gold with copper, this alloy exudes a classic golden hue.
  2. White Gold: Crafted from gold combined with nickel or palladium, it has a silvery appearance.

The Caratage Scale:

To gauge the purity of gold items in Bangladesh, jewelers employ the caratage scale, ranging from 1 to 24. Higher carat values indicate purer gold. For example, 24 carats represent 99.9% pure gold. The term "karat" is used in the US and Canada, while "carat" is standard elsewhere.

Calculating Caratage:

Determining the caratage of a gold piece involves dividing the total gold mass by the total object mass, then multiplying by 24. For example, if a gold pendant weighs 5.4 grams and contains 4.85 grams of gold, the caratage is calculated as follows:

((4.85 / 5.4) * 24) ≈ 21.56

Rounding down to the nearest whole number, the pendant is considered 21k gold.

Expressing Purity in Percentage and Parts Per Thousand (ppt):

Gold purity can also be expressed in percentage terms and parts per thousand (ppt), known as the millesimal fineness system. For instance, a 21k gold pendant is approximately 89.815% pure gold or has a millesimal fineness of 898 out of 1000.

Converting Carats:

To convert carats to a percentage, divide the carat value by 24 and convert the decimal to a percentage. For example, 18k gold is at least 75% pure (18/24 = 0.75).

To convert carats to the millesimal fineness system, divide by 24 and use the first three digits after the decimal point. For example, 22k gold corresponds to a millesimal fineness of at least 916 (22/24 = 0.91667).

Understanding gold purity and caratage empowers Bangladeshi jewelry buyers to make informed decisions, ensuring they acquire pieces of lasting value and significance. Whether it's a wedding ring or a family heirloom, knowing the purity of your gold jewelry is a testament to its enduring worth.