Gemstone anatomy is very similar to that of a diamond. In a standard brilliant cut, there is a table, crown, girdle, pavilion, and culet just like that of diamonds. Unlike diamonds, however, there are no defined proportions to follow.
The overarching goal of a gemstone manufacturer is to create the best possible cut for that stone. The outcome is a result of the cutter’s experience and knowledge and ability. Always remember that beauty is in the eye of the beholder, and your gem should look perfect to you!
A gemstone, unlike a diamond, has no defined proportions. Hence, it is available in proportions that are largely determined by the cutter or manufacturer.
The basic idea is to maximize the yield (the weight of the stone, after the stone is cut and polished). And because there is no set of proportions that the manufacturer has to follow, he uses his knowledge to bring out the best possible outcome.
A set of proportions which is known as ‘machine cut’ is the nearest a manufacturer can achieve to the ideal cut.
A Breakdown of Gemstone Proportions
When it comes to symmetry, a manufacturer follows the best possible cut to maximize the yield of the cut and polished stone. It is a total measurement of the shape, placement and size of the facets and is entirely dependent on the skill of the cutter.
They must ensure that all the facets are evenly placed and look symmetrical when the stone is viewed face up. The face up look of a gemstone is the most important.
Round Rhodolite Garnet Gemstone
Polish in a gemstone is just like that in the diamond. This means that the manufacturer aims to achieve the best possible glow and shine, given the hardness of the stone. A good polish will increase the ‘luster’ of the stone. The higher the luster, the better looking the stone is.
What we need to understand is that the stronger the stone, the better the polish and the subsequent luster, as softer stones do not polish as well. Most of the gemstones have a polish that falls under ‘vitreous’ range, in other words, it is glass-like.
Blue Sapphire is 9 on Mohs Scale of Hardness Allowing for a Beautiful Polish Luste
A gemstone’s facets are cut and placed to specifically accentuate its sparkle and fire as light enters and is reflected back to the eye. When it comes to facets, the number and arrangement are not defined and hence the manufacturer will use the best possible number and arrangement of facets to get the best performance from a gem. Most gemstones are cut into shapes that highlight color and sparkle. The most common cuts are the brilliant, step, mixed, rose, briolette, and cabochon.
Brillant
When the shape of the facet is mostly triangular or kite shaped, the faceting style is called ‘brilliant faceting style’. The classic round brilliant cut has 58 facets, for example. This cut is the traditional cut for solitaire rings of any kind, including engagement rings.
Round Teal Sapphire Jewelry Set
Step
When the facets are arranged in ‘steps’ or rows in parallel with the table, the faceting style is called ‘step cut’. Depending on the size of the stone, more step facets may be placed. An example of a step cut is the emerald cut, which is rectangular. It is a common cut for stones such as emeralds, diamonds, and amethysts, among others.
Step Cut Amethyst Gemstone Ring
Step Cut Blue Sapphire Engagement Ring
Mixed
When we have a combination of brilliant and step cut facets in the same stone, the faceting style is called ‘mixed’. Most of the gemstones follow this faceting style as it brings out the best look while retaining more weight from the original rough material.
Mix Cut ( Emerald – Cushion) Engagment Ring
Rose
The rose cut is an antique style, developed in the 1500’s and designed to enhance a stone’s sparkle in candlelight. It is a faceting style where triangular facets are used all the way to the top. These stones do not have a table and at the same time they do not have a pavilion. If this faceting style is used on the crown and the pavilion, it is known as ‘Double Rose’. This is a popular faceting style for flattish pieces of diamond rough, however it is not an ideal cut for getting the most brilliance or scintillation from a gemstone.
Rose Cut Morganite Set in Rose Gold with A Diamond Halo.
Briolette
A gemstone is known as a ‘briolette’, when it is manufactured in a drop shape with faceting on all sides. The high number of facets brings out the sparkle of the stone. Popular as a pendant shape, they are usually used for stones that are hanging in jewelry such as earrings or necklaces.
Loose Briolette Gemstones
Cabochon
The cabochon is a polished, dome-shaped cut with a flat base. This cut style was used before faceting techniques and tools had been developed, and allows us to experience a gem’s unique colors without any play of light, as well as see deep into the body of the gemstone without much reflection back.
This works well for stones that are opaque or translucent with unique identifying markers like a star sapphire or opal. Sometimes the dome has a point at the top, like a rounded pyramid. The flat base makes it well suited for use in jewelry settings, and it certainly makes a very big statement in any ring.
Loose Opal Cabochon Gemstones
Opal Cabochon Engagement Ring
