Core Technology

HPHT Diamond Synthesis:
The Complete Technical Pipeline

From biological carbon source to gem-quality diamond — a seven-stage precision manufacturing process operating at 5.5 GPa and 1,450°C.

Process Overview

High-Pressure High-Temperature Crystal Growth

HPHT is the established industrial method for producing gem-quality laboratory-grown diamonds. Our process replicates the natural conditions of diamond formation — extreme pressure and temperature — within a controlled manufacturing environment.

The HPHT method produces diamonds with the same optical, physical, and chemical properties as natural diamonds. The key differentiator in memorial diamond production is the carbon source: rather than generic carbon feedstock, we use carbon extracted and purified from biological materials submitted by partners and end customers.

5.5 GPa

Synthesis Pressure

1,450°C

Growth Temperature

~60 Days

Growth Cycle

HPHT Process Parameters

Pressure Range 5.0 – 6.0 GPa
Temperature Range 1,350 – 1,600°C
Growth Chamber Type Belt / Cubic Press
Catalyst Alloy Fe-Ni-Co System
Carbon Source Purity ≥ 99.95%
Typical Output Size 0.3 – 2.0 ct rough
Quality Consistency 98.7% Batch Rate
Stage 01

Biological Material Intake

Carbon-bearing biological materials are received, catalogued, and assessed for carbon content and sample viability.

Compatible Carbon Sources

Human Hair

Minimum 0.3g. Keratin-based carbon extraction with high yield.

Pet Fur

All mammalian keratin. Compatible with cat, dog, horse, and other species.

Cremated Ashes

Carbon-rich residue. Requires extended purification stage.

Flowers & Plants

Botanical cellulose and lignin carbon. Seasonal viability assessment.

Intake Protocol

1

Sample Receipt & Documentation

Unique batch ID assigned. Chain-of-custody log initiated. Photo documentation of sealed sample container.

2

Carbon Content Assessment

Preliminary spectroscopic analysis to estimate available carbon mass and identify potential contaminants.

3

Sample Viability Confirmation

Go/no-go decision based on carbon yield estimate. Partner notified of any material constraints.

Stages 02 – 03

Carbon Extraction & Purification

The proprietary stage that determines diamond quality. Our 2012 national invention patent covers the complete bio-carbon-to-diamond purification pipeline.

Stage 2: Carbon Extraction

Biological materials undergo multi-phase processing to liberate and isolate carbon content. This stage removes organic binders, moisture, and non-carbon biological compounds through controlled thermal and chemical decomposition.

  • Thermal decomposition at controlled atmosphere
  • Acid digestion to remove mineral contaminants
  • Initial carbon fraction isolation
  • Mass yield documentation

Stage 3: Carbon Purification

The extracted carbon fraction undergoes rigorous purification to achieve 99.95%+ purity — the threshold required for successful diamond synthesis. This is the most critical quality-determining stage of the entire pipeline.

  • Multi-stage filtration and washing
  • High-temperature purification under inert atmosphere
  • Spectroscopic purity verification (≥99.95%)
  • Purified carbon sealed for graphitization
Stage 04

Graphitization

Purified amorphous carbon is converted into crystalline graphite — the direct precursor material for diamond synthesis. This structural transformation is essential because diamond growth requires an ordered carbon lattice as the starting material.

Process Temperature

2,000 – 3,000°C under vacuum or inert gas atmosphere

Duration

12 – 48 hours depending on carbon mass and source material

Structural Outcome

Hexagonal graphite crystal structure with layered atomic arrangement

Quality Checkpoint

X-ray diffraction confirmation of crystalline graphite phase

Why Graphitization Matters

Structural Precondition

Diamond is a cubic crystal of carbon. Graphitization creates the ordered hexagonal precursor that restructures into diamond under HPHT conditions.

Growth Kinetics

Graphite-to-diamond conversion is faster and more controllable than amorphous-carbon-to-diamond, enabling the ~60-day cycle.

Quality Impact

Incomplete graphitization leads to inclusions, color defects, and structural weakness in the final diamond.

Stage 05

HPHT Crystal Growth

The core synthesis stage. Graphite is transformed into diamond through sustained high-pressure, high-temperature conditions in a synthesis chamber.

Pressure Application

The synthesis chamber is pressurized to 5.0 – 6.0 GPa (approximately 55,000 atmospheres) using a belt-type or cubic multi-anvil press.

Equivalent to the pressure at ~180 km depth in Earth's mantle

Temperature Control

Temperature is elevated to 1,350 – 1,600°C, creating a thermal gradient across the growth cell that drives carbon transport from graphite to the diamond seed.

Precision ±5°C maintained throughout the growth cycle

Growth Duration

The growth cycle runs continuously for 40 – 70 days depending on target carat weight. Larger diamonds require extended growth periods.

Growth rate: ~0.01 – 0.03 mm/day depending on conditions

Growth Chamber Configuration

Graphite Source

Purified bio-carbon graphite positioned at the high-temperature end

Catalyst Alloy

Fe-Ni-Co molten metal solvent that dissolves and transports carbon

Diamond Seed

Small natural or synthetic diamond crystal that initiates growth

Thermal Gradient

Temperature differential drives carbon from source to seed

Stage 06

Diamond Processing

After synthesis, the rough diamond undergoes cutting and polishing to achieve the desired shape and optical quality. Our processing protocol prioritizes maximum carat retention while optimizing for clarity and brilliance.

Rough Assessment

Microscopic examination to identify optimal cut plan. Inclusions mapped and documented.

Precision Cutting

Laser or mechanical sawing followed by bruting to create the girdle and basic shape.

Polishing & Faceting

Multi-stage polishing on scaif to achieve the final facet arrangement and surface luster.

Stage 07

Grading & Delivery

Every finished diamond is graded and documented before delivery. Our certification system provides partners with the documentation needed to present a complete, verifiable product to their customers.

4C Grading

Carat weight, color grade, clarity grade, and cut quality assessed per industry standards.

CCIC Traceability Code

National traceability QR code assigned. Full chain-of-custody documentation available via scan.

Gemological Certificate

Chinese Gemological certification standard. IGI certificate available as optional add-on.

Production Video

Key stage video documentation compiled for partner and end-customer access.

Intellectual Property

National Invention Patent — Carbon Extraction & Diamond Synthesis

Our core carbon extraction and purification technology is protected by a national invention patent granted in 2012. This patent covers the complete pipeline from biological material intake through purified carbon production, establishing a proprietary foundation that differentiates our manufacturing process from generic lab-grown diamond producers.

Patent Type

National Invention Patent

Granted

2012

R&D Origin

Since 2003

Patent Coverage Scope

  • Biological carbon extraction from keratin-based materials
  • Multi-stage purification to 99.95%+ carbon purity
  • Graphitization of amorphous biological carbon
  • HPHT diamond synthesis from bio-carbon graphite
  • Integrated quality control and traceability system

Ready to Partner on Memorial Diamond Supply?

Discuss OEM manufacturing, white-label supply, or custom technology requirements with our partnership team.