Jeweller - August 2021

GEMSTONE FEATURE | Lapidary Design
by JUSTIN K PRIM
Once upon a time, buyers of coloured stones
were solely focused on colour and size,
but in the 21st Century, gemstone and
jewellery customers are becoming more aware
of the effect of the cut on coloured gemstones.
Gemstone grading laboratories started issuing cut grades
on diamonds in 2006 – which caused the entire diamond
industry to become more conscious of the cutting quality –
but in coloured gemstones, this revolution has yet to arrive.
Some laboratories are starting to issue cut grades
on reports and a few have even offered the option of
including the cutter’s name as an attempt to add value
and provenance to a gemstone.
Each type of cutting style offers unique benefits to the
gemstones, whether that means enhanced colour, weight
retention, or more sparkle.
Each cutting style offers unique
benefits to the gemstones, whether
that means enhanced colour,
weight retention, or more sparkle"
When the cutter picks up a piece of rough in order to plan
the cut, they must make many complex decisions around
how the stone will be cut, with respect to the rough
stone’s original shape, colour, and weight.
In an attempt to make gemstone and jewellery buyers
more aware of the benefits of different types of cutting,
this guide outlines the benefits and differences between
some of the most popular cuts.
Cutting quality
A disclaimer must be made in a guide such as this –
not all cutting is equal.
The stones that are about to be presented here are
perfectly cut to represent the best qualities of each cut.
When you enter a gem market, this is not always – and
not usually – the case.
Often, we find stones in the market whose cut has
been compromised in order to make the best use
of the original rough.
For buyers, this means that we might see a cut that
fails to present beauty in some way because it has a
window that is leaking light, a poorly shaped outline,
is unintentionally asymmetrical, or a myriad of other
problems which are outside the scope of this article.
Chaumet 'Labyrinthe' brooch
from the Perspectives Collection,
featuring oval rubellite, baguette
tourmaline, jade and brilliant-cut
diamond
Chopard Red Carpet Collection
Earrings, featuring brilliantcut
topaz, cabochon sapphire,
and brilliant-cut orange and
blue sapphire
Van Cleef & Arpels 'Iwamoto'
ring from the Sous Les Étoiles
Collection, featuring octagonal
sapphire, hexagonal emerald,
green tourmaline, baguette
diamond
A note on shape
Before we get into cutting styles, a word must be said
about the shape of the stone. In almost every example in
this article, the outline shape of the stone and the cutting
style are independent features of the cut.
For example, a round stone is often cut in the Brilliant
style but it’s also possible for it to be cut as a Step cut, a
Portuguese cut, a Mixed cut, and many more.
Almost any cutting pattern can be applied to any shape,
so there is a creative choice to be made by the cutter
when designing the stone.
The outline shape will usually follow the shape of the
rough material but the cutting pattern will be chosen
based on the colour and tone of the stone as well as
the optical effect and visual feeling that the cutter
wants to create.
Major cutting styles
Let us begin our journey through the world of gem cuts
with the three major styles. There are some cutting
styles that we see being used over and over in every
type of gemstone.
These three styles represent the most popular cutting
styles used throughout the world of coloured gemstones.
» Brilliant – The Brilliant cut is the best cut for creating
sparkle and flash in a stone. It reflects more white light
and gives the stone a feeling of scintillating light. It’s a
great cut for adding life to a stone, especially if it’s light
or white coloured.
The downside to this cut is that it loses much more of the
stone’s original rough weight and also, since it adds white
light into the stone, the colour saturation decreases.
If you have a stone with a moderately deep colour
saturation and you give it a Brilliant cut, you tend to lose
some of that colour; whereas if you have a dark stone,
the Brilliant cut might be just the thing to lighten it up.
The Brilliant cut was originally made to enhance the
brilliance of diamonds in the 1600s but was quickly
adapted for use in the coloured gemstone world as well.
Any stone can be cut as a Brilliant, though since this is
the cut that loses the most weight, we see it used more
often in stones of lower value as well as melee.
It’s a cut that is regularly used in garnet and topaz, and
rarely seen in emerald and tourmaline; it would be rare
to find a Brilliant cut ruby and slightly challenging to find
a Brilliant cut sapphire.
» Step – Step cut means that the cut is composed of
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