Memorial diamonds are genuine lab-grown diamonds made using carbon extracted from a person's or pet's hair. The process combines carbon purification, graphitization and HPHT growth under controlled pressure and temperature.
The result is not a simulant such as cubic zirconia or moissanite. It is carbon in a cubic diamond crystal structure, with the same core physical, chemical and optical properties as a mined diamond. Specialised gemological equipment can identify its laboratory-grown origin.
Here is exactly how it works.
The Science: Why Hair Contains a Diamond
Hair is approximately 45–51% carbon by mass. That carbon is locked into the protein keratin — the same fibrous protein that forms nails, wool, feathers, and hooves. Keratin is remarkably carbon-dense, which is why hair is an ideal source material for diamond creation.
Diamonds are entirely carbon. Not a compound, not an alloy — pure elemental carbon (symbol C, atomic number 6), arranged in a specific tetrahedral crystal lattice called a cubic structure. Every carbon atom bonds to four others in this lattice, which is what gives diamonds their extraordinary hardness (10 on the Mohs scale — the hardest natural substance).
When carbon from hair is purified and placed under the right conditions — extreme heat and pressure — it crystallises into exactly that structure. The atoms bond, the crystal grows, and a diamond forms. The fact that the carbon came from hair rather than a geological deposit doesn't change the crystal it produces. Chemistry is chemistry.
Key fact: A memorial diamond is not a copy of a diamond, a simulant, or a diamond-like material. It is a diamond. The same carbon atoms, the same cubic crystal structure, the same properties. It will scratch glass, pass a thermal conductivity test, and refract light identically to any other diamond.
The Seven-Stage Process
Silmaril coordinates a seven-stage production process from sample intake to finished jewellery.
Hair sample submission
Silmaril provides sample preparation and posting instructions. Silmaril recommends approximately 10g of clean, dry human hair and approximately 20g of pet fur where available to provide processing margin. The technical requirement may be lower depending on sample condition and target carat.
Life-ID assignment
On receipt by Silmaril, your sample is logged and assigned a unique biological Life-ID. This identifier is physically attached to your sample and tracked through every subsequent stage of production. Collection, handover, purification, growth, cutting, setting, and dispatch are documented with photos and milestone video where available, creating a visual chain of custody. From this point, your loved one's material is never combined with another customer's material — One Guest, One Chamber, always.
Carbon extraction and purification
Controlled thermal and chemical processing isolates the carbon fraction from keratin. Multi-stage treatment purifies the carbon to at least 99.95%, with verification before it proceeds.
Graphitization
Purified amorphous carbon is converted into crystalline graphite in a controlled high-temperature environment. This ordered graphite is the direct feedstock required for HPHT growth.
HPHT crystal growth (35–50 days)
Bio-carbon graphite is loaded into a dedicated HPHT growth cell alongside a small diamond seed and metal catalyst. At typical conditions of approximately 1,450°C and 5.5 GPa, carbon migrates through the catalyst and crystallises on the seed.
Cutting, polishing, and 4C grading
The rough diamond is assessed, cut, faceted and polished. The finished stone is graded for carat, colour, clarity and cut. GIA or IGI certification can be arranged on request.
Jewellery setting and delivery
The graded diamond is set into The Guardian or The Warmth in 18K gold, inspected, packaged and returned by insured courier to your New Zealand address.
What Quality Can You Expect?
Silmaril targets VS clarity or better and D to H colour. VVS can occur, but every crystal grows individually and final grades are confirmed only after cutting and 4C assessment.
To put those grades in context:
- VS clarity or better: Target grade, with VVS possible but not guaranteed before production.
- D–H colour: Colourless to near-colourless; final colour depends on purification and controlled growth conditions.
Every Silmaril diamond is a 0.57ct stone. If you would like GIA or IGI gemological certification, contact us at [email protected] for current certification pricing.
HPHT vs CVD — What's the Difference?
There are two main methods for creating lab-grown diamonds: HPHT and CVD (Chemical Vapour Deposition). Memorial diamond studios — including Silmaril — use HPHT, for a specific reason.
CVD grows diamonds from a carbon-rich gas in a low-pressure chamber. Memorial diamond manufacturing instead commonly uses HPHT because purified biological carbon can be converted into solid graphite feedstock for a controlled growth cell.
HPHT works with graphite as the carbon source. Purified biological carbon is graphitized, then placed in the growth cell with a catalyst and diamond seed. Traceability therefore depends on documented sample handling, batch separation and production records across every stage.
Summary: HPHT is well suited to memorial diamond production because purified biological carbon can be converted into graphite and used as the growth feedstock under controlled pressure and temperature.
Why Not Ashes?
Cremation ashes are often misunderstood as a viable source of carbon for diamond creation. In reality, the cremation process changes the chemistry of the remains significantly.
When a body is cremated at 760–1150°C, most organic carbon is burned off. What remains is predominantly calcium phosphate (from bone), along with metal oxides, silica, and other mineral compounds. The carbon content is minimal and the impurity levels are high — both incompatible with the HPHT process, which requires 99.95%+ pure carbon.
Hair, by contrast, is rich in keratin and retains its carbon through normal collection. A 10g hair sample yields sufficient pure carbon to grow a 0.57ct diamond. Ashes cannot replicate this.
Silmaril works exclusively with hair. If you are in a situation where only ashes are available, we explain the options on our ashes-to-diamond page.
Is the Diamond Traceable to My Loved One?
This is the most important question most people ask, and the answer is yes — through three layers of assurance:
- One Guest, One Chamber protocol: Your hair sample is placed in a dedicated HPHT chamber. No other customer's material is ever present. This is a physical operational guarantee, not just a policy.
- Life-ID tracking: Your sample receives a unique identifier when received by Silmaril that follows it through every stage — logged, labelled, and never separated from your material through purification, growth, cutting, and setting.
- Photo and video documentation: Each production stage is documented where available and tagged to your Life-ID, including collection, shipping handover, purification, growth, cutting, setting, and dispatch.
The combination of physical separation (dedicated chambers), documentary tracking (Life-ID), and visual evidence (photos and milestone video) provides a layered chain of custody that helps substantiate that the finished diamond is grown from the submitted hair sample.