I’m often asked why some one carat diamonds look larger or smaller than others. it’s important to understand that the term carat is descriptive of weight not necessarily of size.
The term carat is derived from the Greek word Keration which literally means carob seed (small horn). Carob seeds come from a flowering evergreen shrub or tree which commonly grow in various regions throughout the Middle East, Mediterranean, Southern Europe and Northern Africa.
Carob seeds were often used by early merchants as a weight measurement for selling gold. It was believed that the carob seed was unique in that all seeds varied little in size and weight. This made them perfect for consistent measurement. It was later found out by researchers that this was not exactly the case but the history of the term and use is undeniable.
In or around 1570 carob seeds begin to be used to measure diamond weight where the term carob evolved into what we use today, carat.
The term carat is defined as being equal to: 200mg (0.2 gr; 0.007055 oz). As you can see carat is a measurement of weight not size. Is it possible that a diamond can look smaller or bigger and still weight the same? The answer is Yes!
The primary goal of any diamond cutter is to maintain weight when cutting and polishing a diamond. Often times the cutter is forced, due to the natural shape of the diamond rough, he must cut a smaller diameter diamond with greater depth in order to maximize weight. The opposite is also true where the cutter must cut a more shallow diamond if the rough is more flat, making the diamond much larger in diameter.
These variations in cut can give a one carat diamond a completely different appearance in size when viewed face up. A one carat diamond cut to proper proportions should measure 6.5mm in diameter. Variations from proper proportion and symmetry can greatly effect the beauty and value of a diamond. See my Value of a Diamond
All diamonds have a unique beauty, but a properly proportioned diamond in the perfect engagement ring will always poses that special WOW factor!!
At D&R House of Diamonds we would love to educate you more about diamonds, please feel free to give us a call and set up an appointment while in Las Vegas!
Owner / Partner
D&R House of Diamonds
Graduate Diamonds GIA