Gemstone Cutting : Terminology

Which shape is the best? The age old debate in the jewelry industry continues every year as shapes go in and out of style. However, there is one shape that continues to be the most highly sought after and timeless shape of all…the round brilliant cut!

Now, you may be asking “What is involved in a standard brilliant cut?” In this blog we will talk about the history and terminology of the standard round brilliant and how each part is cut to precise measurements that allows the gemstone to perform at its maximum capabilities.

The first faceted stones appeared in the late 14th century. Many lapidaries passed down the knowledge of gem faceting as family secrets. During the 19th century, the art of faceting gemstones became available to amateurs and hobbyists. Fast forward to today and you can find all kinds of literature and videos on how to perform this art. The standard round brilliant begins with the craftsman rounding out the rough stone, then a combination of facets in geometrical patterns are cut around the stone. This maximizes the optical properties of the gem and will generate brilliance that is pleasing to any beholder. There is a total of 57 facets in a standard brilliant, however, this can vary depending on the stone.


The Crown

The crown is the top section of the gemstone. It is approximately ⅓ of the height of the finished gem. A total of 33 facets make up the crown. The facets are divided into 8 main facets, 16 girdle facets, 8 star facets and 1 table facet.


The Pavilion

This is the bottom section of the gemstone. It is approximately ⅔ of the height of the finished gem. A total of 24 facets make up the pavilion. The facets are divided into 8 main facets, 16 girdle facets.


The Girdle

This is the section of the gemstone that connects the crown and the pavilion. The maximum height of a girdle in a standard brilliant, must not exceed 5% of the finished gem’s height.


The Culet

This is the very bottom point of a gemstone. It can be cut as a small, flat facet to prevent the gem from fracturing. This is a common practice to help the durability of stone.


There you have it; this is the parts of a standard round brilliant. Not all gemstones are cut into this shape, many times the shape is dependant on what type of stone is being cut, and how included the rough is. The decision of what shape to cut the stone into is essential as it will affect all the steps that we will learn about in the next blog post.


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