Diamond Cutting & Polishing
A 10-stage journey from rough crystal to graded brilliant
Every diamond that passes through our hands undergoes a meticulous ten-stage transformation. From the initial assessment of the rough stone to the final grading, each step demands expertise honed over four decades. Our own sawmill — a rarity in the industry — gives us complete control over the process.
Pre-sorting the Raw Material
Every diamond begins its journey at the sorting table. Our master sorters evaluate each rough stone by hand, assessing its shape, size, clarity, and potential yield. This critical first step determines the optimal cutting strategy for each individual stone — whether it will become a brilliant, a marquise, or a pear. With decades of experience, our sorters can read a rough diamond the way a sculptor reads a block of marble.
Designing the Cut
Using a combination of traditional expertise and modern planning, each stone is studied to determine the ideal cut that maximizes both weight retention and brilliance. The designer must balance commercial considerations — retaining as much carat weight as possible — with the optical physics that create a diamond's fire and scintillation. A well-designed cut can make the difference between an ordinary stone and an extraordinary one.
Marking for Precision
Once the cut is designed, the stone is carefully marked with India ink to guide the sawyer. These lines indicate exactly where the diamond must be split or sawn. Precision at this stage is paramount — a marking error of even a fraction of a millimetre can mean the difference between a flawless result and a compromised stone. Our markers work under magnification, using steady hands refined by years of practice.
Setting the Stone
Before sawing can begin, the rough diamond must be firmly secured in a copper holder called a dop. The stone is set using a special solder that holds it precisely in position while allowing the saw to cut along the marked line. Proper setting is crucial — the stone must be perfectly aligned with the saw blade, and the holding must be rigid enough to withstand the intense vibration of the cutting process without shifting.
Diamond Sawing
Our own sawmill — a rarity that places us ahead of 99% of cutting houses worldwide — uses phosphor-bronze blades charged with diamond powder to cut through the hardest natural material on earth. Sawing a single stone can take anywhere from 30 minutes to an entire week, depending on size and crystal structure. A single worker supervises up to 20 saws simultaneously, monitoring each cut's progress with practised vigilance.
Bruting — Shaping the Round
In this ancient technique, one diamond is literally rubbed against another to create the round girdle shape that defines a brilliant cut. The bruter works at a lathe where two diamonds spin against each other at high speed. It is one of the most physically demanding stages — and one of the most remarkable, as only a diamond is hard enough to shape another diamond. Above 1000°C, diamond graphitizes, so a borax coating is applied to prevent damage during this intense process.
Faceting — Lower Part
The lower facets of the diamond — known as the pavilion — are ground onto a spinning cast-iron disc impregnated with diamond dust. Each facet must be placed at precisely the correct angle to create the internal reflections that give a diamond its brilliance. The polisher works with a tang, holding the stone against the wheel with controlled pressure. Our Belgian presspots are imported and used only once, then sold to competitors who reuse them ten or more times.
Faceting — Upper Part & Stars
The crown facets and star facets are the final touches that complete the diamond's optical architecture. A skilled star-facet grinder produces approximately 1,200 facets per day — that is roughly one every 24 seconds — each placed with pinpoint accuracy. The star facets are particularly demanding: tiny triangular facets at the top of the crown that must align perfectly with both the bezel facets and the table. This is where German precision truly shines.
Quality Control
Quality control is not a single step but a continuous discipline woven throughout the entire cutting process. Each stone is inspected at least six times during grinding, and our graduates use a 20x loupe — more accurate than the industry-standard 10x — to examine every facet. Between 10% and 15% of stones are sent back for rework. We believe that a diamond that leaves our facility carries our reputation, and we take that responsibility seriously.
Grading & Sorting
The finished diamonds are graded according to the international 4C system — cut, colour, clarity, and carat weight — and sorted into matched parcels for our clients. Our graders are trained to the exacting standards of European gemological institutes. Each stone receives a final assessment that determines its market classification. The journey from rough crystal to graded brilliant is complete — a transformation that embodies four decades of accumulated expertise.
Ready to Work With Us?
Whether you need precision-cut brilliants or have rough diamonds requiring expert processing, our four decades of experience are at your service.