Gemstone(jewel) certificate: definition and usefulness
Gemcutting is a technological process of treating the gemstone to give it a certain shape and fully emphasize the optical characteristics of the mineral. Shapes and proportions of different cuts are not accidental. They are extremely precise, so that the rays, refracted in the facets of the stone, create the maximum play of light.
Test, test, test...
Test, test, test...
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There are around 25 different kinds of cutting in the jewelry world. The choice depends on the physical and optical characteristics of the raw gemstone, it’s shape, the number and location of the defects and inclusions. It’s extremely important to save the weight of the stone and highlight it’s natural beauty in the cutting process.
Let’s look at the structure of a cut gemstone to better understand the nuances of different cuts.
A gemstone consists of the upper part, a crown, and the lower part, a pavillon. Between them on the widest line lies the girdle, a narrow facet that wraps the entire stone. Exactly in this place the stone is being set into a jewelry piece and gets the lab certificate engraved.
Culet is the lowest point of the stone. Table is the biggest flat facet on the top of the stone.
A cut may be divided into 3 groups: tumbling, faceting and mixed.
Tumbling cut is actually polishing, because those gemstones don’t have facets, they only have smooth polished surfaces of a certain shape. Usually this cut is applied to semi transparent and opaque jewelry gemstones.
The most common kind of this polished cut is cabochon.
It’s a dome shaped cut with the lower part being flat, and the upper part being prominent. It’s mostly chosen for nephrite, turquoise, amber, malachite, onyx, opal, etc.
Faceting cut is used with clear precious gemstones. It brings out the shine, amplifies the color and highlights optical characteristics.
There are many types of faceting cuts. Let’s meet the ones that are the most widely used on the jewelry market.
With this one, the facets are arranged parallelly and above each other, just like ladder steps. The wide upper platform is made in the form of a polygon, and the side facets are made in the form of trapezoids or isosceles triangles.
It’s a step cut in the shape of a rectangle.
This type requires high level clarity of the gemstone, because even the tiniest defects will be obvious to a naked eye. It’s used for treating small gemstones: adamants, rubies, emeralds, topazes.
This cut physically resembles “baguette” but with oblique angles. 58 or 65 facets. It received the name “Octagon” because of the number of facets. Also, the name “emerald” is applied because originally this cutting type was used precisely for these gemstones.
One more type of an octagonal cut, but it’s square, not rectangular. It’s named after a dutch jeweller, Joseph Asscher, who developed it in 1902. This cut results in a big loss of the gemstone’s weight.
It consists of many taper-shaped facets that favorably bring out the color and create max play of the light in it.
Round diamond cut
It is the most commonly used type for cutting diamonds which helps to reveal the whole play of light in this crystal. The biggest shortcoming of this cut is that while cutting the raw stone, it may lose up to 60% of its initial weight.
Classic or complex diamond cut has 57 facets: 33 facets are located on the crown and 24 are placed on the pavilion. It’s used for diamonds that weigh less than 1 carat.
Simplified diamond cut consists of 33 or 37 facets. It’s used for cutting small and average-sized stones that weigh up to 1 carat.
Its biggest benefit compared to round one is that it saves the weight of the gemstone. Usually has 57 facets but the number may vary. Mostly used for big clear gemstones, for instance, aquamarine, amethyst, sapphire, topaz.
It’s an oval with pointed ends, and has 57 facets. Most often used for rings, but sometimes can be used for necklaces and earrings. Used for adamants, amethysts, emeralds, rubies.
It’s a hybrid of round diamond cut and “Marquise”. 57 facets. From above it visually resembles a drop, one end is rounder, the other is pointed. Most widely used for aquamarines, amethysts, topazes.
The most popular kind of quadrangular cut. 65 or 75 facets. Unlike the round diamond shape, it saves more of the raw material.
Square or rectangular cut with rounded corners. 72 facets. It’s used for adamants, amethysts, sapphires, emeralds, rubies, quarts.
Tapered cut of a triangular shape. 44 facets. The gemstone’s angles may be pointy, beveled or rounded, some may have a sharp triangular table. Mostly used for light-colored gemstones: adamants, aquamarines, beryl, white sapphire.
Considered to be one the most complex and expensive taper shaped cuts. 59 facets. Most commonly used for exclusive jewelry with rubies, amethysts, topazes, garnets and colored adamants.
Mixed cut includes parts of different types of cuts. For example, step and tapered cuts, or tumbled and facet cuts.
It is a combination of step and diamond cuts, combining the elegance of “Emerald” and the beauty of “Princess”. This cut has a rectangular or square shape with beveled angles and may have from 65 up to 89 facets.
There is no “right” cut that you must exclusively prefer. If you are selecting a gemstone, you should base the choice on your goals and esthetic characteristics for a specific gemstone. But it’s better to buy round cut diamonds for investment. They are known to be the most marketable.