Knowledge Center
Diamond Manufacturing Process
A step-by-step look at how lab-grown diamonds are made.
Manufacturing Process
Rough Lab-grown Diamond Manufacturing Process
| Process Stage | Description |
|---|---|
| Substrate (Seed) Preparation | Involves cleaning the diamond seed using ultrasonic and acid baths, then placing it on a molybdenum or quartz holder inside the reactor chamber. |
| Plasma Generation & Growth | MPCVD reactors use a methane and hydrogen gas mixture, ignited by microwave energy to create plasma. Operating conditions: 900–1050°C, 100–130 Torr, and 6 kW microwave power. Growth lasts 7–28 days depending on requirements. |
| Post-Growth Cooling & Removal | The chamber is vacuum-purged and slowly cooled to prevent cracking. The diamond is then removed and cleaned with acids to eliminate graphite or other impurities. |
| Acid Cleaning & Polishing | Rough diamonds undergo chemical cleaning using HCl, HNO₃, or mixed baths, followed by optional mechanical polishing for further assessment. |
| Final Inspection & Grading | The diamonds are inspected for size, colour, clarity, and structure using optical microscopes, Raman spectroscopy, and laser mapping tools. |
Polishing Process
Lab-grown Diamond Polishing Process
| Process Stage | Description |
|---|---|
| Planning and Mapping | The rough diamond is scanned and analysed using 3D laser scanners and inclusion mapping software. |
| Cleaving / Laser Sawing | The diamond is divided into workable pieces using fibre or green laser systems, preparing stones for polishing. |
| Bruting (Shaping) | Automatic bruting machines shape the diamond girdle, forming the basic outline, such as round or cushion. |
| Faceting (Blocking) | The first 18 main facets are cut with a polishing tang and scaife (a rotating cast iron wheel with diamond dust). |
| Final Polishing | The remaining facets are added and polished for optical symmetry, using diamond powder on the polishing wheel. High precision and symmetry are essential. |
| Quality Control & Certification | Finished stones are inspected for symmetry, polish, and brilliance, and may be graded. Robotic methods do not apply to certain hand-finishing stages. |
The Technology at the Core
How Are Lab-Grown High Quality Seeds Made?
Every Anjali LabTech (formerly known as Anjali Diamonds Private Limited) begins with a high-quality diamond seed — a thin slice used as the base for new crystal growth. Our seeds are precision-cut to an exacting flatness, since any imperfection carries through to the final crystal. Each seed is screened for defects before entering the MPCVD chamber.