Understanding the Carat

Understanding the Carat

Written by : Posted on January 26, 2011 : 4 Comments

Unique Gold Compass Pendant with Hallmark

Yellow and White Gold Compass Pendant (photo: Kiff Backhouse)


Since antiquity, the Carat (ct) has been a unit of measurement for precious stones. The term is derived from the kernel of the carob bean (from Greek keration). As such, the Carat – and therefore the price – of the stone being sold depended on the size of bean the vendor was using as his counterbalance!

These days, the Carat has gone metric and is now equivalent to 0.2g.

Beware, however, the folks boasting a large Carat gemstone; some stones may weigh a fair bit but have a lot of bulk just to boost the Carat. For example, a dark gemstone with steep sides may have an impressive Carat, but only the polished surface can be appreciated once it’s set into jewellery.


Karat is a term used by the goldsmith as a measure of quality.

It has no relation to the actual weight of the gold. Instead, it refers to the proportion of pure gold in the piece of jewellery. For example, 18 Karat gold is 75% pure gold and 9 Karat gold is 37.5% pure gold.

My jewellery creations are tested for purity at Goldsmiths’ Hall in London so you can always be assured of the quality of the metals used.


And now to the Carrot. This is a crunchy, orange vegetable that can evoke ghastly memories of school dinners and coleslaw.

Personally, I find it makes excellent soup!


  1. I love this lesson!!! 🙂

    gah your items are so gorgeous. They speak to me. I am going to save my pennies. I am. And my centissimi too.