How We Manufacture Lab Grown Diamonds
From growth chamber to certified stone - our process at the Surat facility, operating since 2018. CVD & HPHT Process.
Anyone can claim to be a “direct manufacturer.” Since 2018, OCS Diamond has actually operated as one — this page shows the process, not just the claim. As GJEPC and Surat Diamond Bourse members, transparency about how our stock is grown and graded is part of how we build trust with buyers we’ve never met in person, especially international clients ordering sight-unseen.
The CVD Process
CVD (Chemical Vapor Deposition) growth begins with a thin diamond seed plate placed inside a vacuum chamber. A carbon-rich gas mixture — typically methane and hydrogen — is introduced and ionized into plasma using microwave energy. This breaks down the gas into carbon atoms, which deposit layer by layer onto the seed, building a diamond crystal from the bottom up over several weeks, depending on target size and quality grade.
The result is a diamond with the same crystal structure, hardness, and optical properties as a mined diamond — because chemically and structurally, it is one. CVD is particularly well suited to producing consistent, high-clarity white stock across a wide carat range, which is why it forms the core of our white diamond inventory alongside HPHT.
The HPHT Process
HPHT (High Pressure, High Temperature) growth replicates the natural conditions under which diamonds form deep in the earth — extreme pressure (roughly 5-6 GPa) and temperature (1,300-1,600°C) applied to a small diamond seed surrounded by a carbon source and a metal catalyst. Under these conditions, carbon atoms migrate to the seed and crystallize into diamond over a period of days to weeks.
We stock both CVD and HPHT as primary growth methods, giving buyers a genuine choice based on their carat and clarity target rather than a single-method offering.
Quality Control & Grading
Every stone entering our inventory is internally reviewed against carat, color, clarity, cut, polish, and symmetry standards by our in-house gemology team before it’s listed — this continuous internal sort is what allows us to refresh live stock every 2 days rather than in large, infrequent batches. Stones are then independently certified through IGI before being made available for trade. This two-step process — our own review plus independent certification — is why we’re comfortable recommending a VS2+ quality floor to buyers who prioritize resale confidence, rather than treating the certificate as the only checkpoint.
What IGI Certification Actually Involves
IGI is ISO 17025 accredited for both natural and lab-grown diamond grading, and pioneered lab-grown diamond certification back in 2005 — they’re not a newer player catching up to the category, they built much of the standard for it. Every diamond submitted goes through a structured process: initial physical examination, precise weight measurement, then color and clarity grading conducted by graduate gemologists under controlled conditions. Graders are randomized between stages specifically to prevent any single individual’s assessment from going unchecked. Every lab-grown stone IGI certifies is automatically laser-inscribed on the girdle with an origin identifier and report number, so the certificate and the physical stone are permanently linked and verifiable.
One practical detail worth knowing: individual IGI certificates are typically issued for diamonds over 1 carat. This is why our melee and smaller stock is generally certified at the parcel level rather than per-stone — not a gap in our process, but standard practice across the industry for smaller goods. Larger individual stones, including 11+ size melee, can be individually certified on request.
Why This Process Matters to You as a Buyer
Every step above exists to answer one question before you ever have to ask it: how do you know what you’re buying is what it’s claimed to be?
Growth method, internal review standards, and independent certification each address a different part of that question — growth method determines the stone’s fundamental characteristics, our internal review catches quality issues before a stone is ever listed, and IGI certification provides an independently verifiable, permanently inscribed record. Combined with the ability to verify a specific stone on a live video call before you pay, this is the full chain of verification behind every listing on this site.
Our Facility
Diamond Cutting
Precision cutting focused on proportions, symmetry, and brilliance.
Diamond Polishing
Careful polishing that brings out the diamond’s clarity and brilliance.
Diamond Quality Inspection
Detailed inspection at every stage to maintain consistent quality.
Advanced Diamond Technology
Modern technology supporting precision, consistency, and efficiency.