What Is the Definition of a Diamond?
Updated: Oct 15
The definition of diamond rests on how carbon atoms are arranged in a crystal. Natural and laboratory-grown diamonds both have diamond material properties; simulants such as moissanite and cubic zirconia are made of other substances. Product labels, invoices and advertising must also communicate origin and follow the rules of the market in which the product is sold. [1][3]
To understand a diamond fully, separate four kinds of information: material, growth origin, treatment status and product name. Material tells us what it is; natural or laboratory-grown describes how it formed; treatment records explain subsequent changes; and the complete product name brings the relevant information to the buyer. This article explains how those distinctions fit together.
Material identity and commercial naming have different scopes. This image illustrates a diamond on a document, rather than an identification report for an actual stone.
Contents
1 What Kind of Material Is Diamond?
Within the jewellery materials discussed here, diamond consists principally of carbon in the characteristic cubic diamond crystal structure. Each carbon atom is covalently bonded to four neighbouring carbon atoms in a tetrahedral arrangement, extending into a three-dimensional network. Both the element and its bonding matter. [1][2]
Graphite is also made of carbon, but its atoms are arranged and bonded differently, giving it very different hardness and optical properties. Elemental composition and crystal structure must therefore be considered together: descriptions such as “carbon-containing” or “high-carbon” do not identify a material as diamond.
Local bonding concepts in diamond and graphite. This is not a complete unit cell, and atoms are not drawn to scale. [1][2]
How Physical Properties Relate to Material
Diamond has a Mohs hardness of 10, a specific gravity of approximately 3.52 and a refractive index of approximately 2.42. These properties reflect its structure and provide useful identification evidence. Professional identification combines appropriate tests; sparkle or a single test result cannot establish the complete material identity. [2][11]
A diamond simulant is a product that imitates the appearance of diamond, rather than a single material category. Moissanite is silicon carbide; cubic zirconia is a zirconium oxide material. Their distinction from diamond is one of composition and structure, regardless of visual resemblance. [3]
2 Can a Purity Percentage Define Diamond?
There Is No Universal Diamond Percentage Cutoff
18K gold and PT950 describe precious-metal fineness. Diamond identification instead considers composition and crystal structure. The Gemological Institute of America (GIA) describes diamond as typically about 99.95% carbon, with trace elements making up the remainder. That is a general compositional description, rather than a pass mark that every diamond must meet. [2]
An analysis showing more than 99% carbon still does not identify the structure in which that carbon exists. Identification must establish the material and its crystal characteristics, rather than compare a composition figure with an assumed threshold. [1][3]
Trace Elements, Inclusions and Added Fillers Have Different Meanings
Trace elements such as nitrogen and boron can occur within the diamond lattice. Vacancies and structural distortion can also affect colour and spectra. Natural and laboratory-grown diamonds may both contain impurities and defects, which can provide evidence of growth history while the material remains diamond. [4]
Inclusions are internal substances or features and may include other minerals. Fillers introduced into fractures after growth are added materials. Their origins and identification significance differ. Visible inclusions alone cannot establish either material or natural versus laboratory-grown origin; identification considers the types, locations and combination of features. [4][6][8]
Distinction | Material significance | Identification considers |
|---|---|---|
Trace elements and lattice defects | Nitrogen, boron and defects can affect colour and spectra | Crystal structure and the overall combination of features |
Inclusions within a crystal | May include material different from the surrounding diamond | Inclusion types and their relationship to growth |
Added fillers or coatings | Introduce additional substances into the product | Diamond body, added materials and treatment status |
Even a high carbon result needs structural identification and a clear understanding of whether the measurement includes inclusions or other materials. Once diamond material is confirmed, growth origin must be identified separately. Natural origin is not calculated as a “natural percentage”.
3 How Are Natural and Laboratory-Grown Diamonds Defined?
Natural and laboratory-grown are the two principal growth origins encountered in the jewellery market. Diamond describes the material; natural and laboratory-grown describe how it formed. Treatment, meanwhile, describes changes made after formation and is a separate attribute rather than a third growth origin.
Natural Diamonds Form Through Geological Processes
Natural diamonds crystallise through geological processes, commonly under high temperatures and pressures in the mantle. Kimberlite and related volcanic processes can carry them towards the surface, where they may remain in primary deposits or be redistributed into secondary deposits. Many natural diamonds are billions of years old; their growth stages and subsequent residence underground are distinct parts of that history. [5][6]
Botswana, Canada, South Africa and Russia are among diamond-producing countries. For the journey from formation to recovery and subsequent processing, read Where Do Diamonds Come From? Comparing the Origins of Natural and Lab-Grown Diamonds. Here, natural origin refers to the crystal having formed through natural geological processes.
Laboratory-Grown Diamonds Crystallise Under Controlled Conditions
A laboratory-grown diamond is a diamond crystal grown under artificially controlled conditions in equipment. A seed is itself a small diamond crystal that provides a basis for further ordered growth as carbon is added. The resulting diamond structure distinguishes this material from simulants made of other substances. [7][18]
The principal methods are high-pressure, high-temperature (HPHT) growth and chemical vapour deposition (CVD). HPHT promotes crystallisation under high pressure and temperature with a suitable growth medium; CVD uses reactions involving carbon-containing gases to grow diamond on a seed surface. Both require controlled conditions, through different equipment and processes. [7]
Natural and laboratory-grown diamonds have essentially the same chemical, physical and optical properties. Details of growth structure, defects and trace elements can nevertheless differ. Laboratories use these features to identify origin as well as material. [6][7]
To explore how a seed becomes a gem-quality diamond and the conditions involved, read How Are Lab-Grown Diamonds Made? From Seed to Finished Gem.
4 Do Treatments Change a Diamond’s Identity?
Colour and Clarity Treatments Need Separate Disclosure
Post-growth treatments aim to change properties such as colour or apparent clarity. A treated diamond needs its material, growth origin and treatment status explained together. After a natural-origin diamond is colour treated, its diamond crystal may remain, but natural origin and natural colour must be assessed separately. [8][9]
HPHT treatment can change the colour of some diamonds; irradiation and annealing can also modify colour. Here, HPHT describes treatment of an existing crystal, a separate stage from HPHT crystal growth. GIA has documented HPHT-treated natural diamonds, illustrating why origin and treatment are separate identification questions. [8][20]
Treatment | Main change | Information to disclose |
|---|---|---|
HPHT colour treatment, irradiation and annealing | Modify colour-related defects or states | Growth origin, treatment status and colour origin |
Laser drilling | Accesses or improves the appearance of certain dark inclusions | Treatment status and method |
Fracture filling | Introduces filler to make fractures less visible | Filling, durability and care requirements |
Surface coating | Adds a thin surface layer to alter appearance | Underlying material, coating and durability |
Fracture filling and coating introduce additional materials. The diamond body and added substances must be distinguished: identifying the underlying material as diamond does not fully describe the product’s composition. Treatment information also matters for care. [8][14]
A Natural-Origin Finding and a Complete Product Name Serve Different Purposes
The World Jewellery Confederation (CIBJO) requires treatment disclosure in its Diamond Blue Book and uses “treated diamond”; it does not accept “treated natural diamond” as the product name. This commercial naming rule is separate from a laboratory finding that the original crystal has natural origin. Read the origin finding together with treatment comments. [9]
Facets, colours and appearances can vary. Material, growth origin and treatment status still need individual identification. Illustrative gemstone image.
5 How Do Laws and Standards Name Diamonds?
Material identification and commercial descriptions answer different questions. The comparison below begins with international naming frameworks, then considers Taiwan, Malaysia and Hong Kong. Laws, national standards and industry guidelines have different status; their application depends on the sales market and the scope of the relevant document.
United States: Material Definition Alongside Origin Disclosure
The US Federal Trade Commission (FTC) Jewellery Guides describe diamond through carbon crystal structure and physical properties in 16 CFR §23.12. Section 23.25 also requires clear disclosure of artificial growth origin. Recognising diamond material and using a complete product name can therefore go together. Examples include “laboratory-grown diamond” and “laboratory-created diamond”. [11][12]
The word “real” also needs context. GIA explains that it is not a precise gemmological term; FTC §23.27 restricts terms such as “real”, “genuine” and “natural” for artificial products. A description that specifies material and natural or laboratory-grown origin gives buyers more information than “real diamond” on its own. [3][13]
International Standards and Other Major Markets
Organisation or market | Document status | Implications for naming |
|---|---|---|
International Organization for Standardization (ISO) | International standard ISO 18323:2015 | Addresses diamond, treated diamond, synthetic diamond and imitation terminology in trade. It is not automatically law worldwide. [15] |
World Jewellery Confederation (CIBJO) | Industry standard: Diamond Blue Book 2024-1 | The unqualified name diamond is based on natural mineral origin; artificial growth and treatment have additional naming and disclosure requirements. [9] |
Bureau of Indian Standards (BIS) | National standard IS 19469:2025 | Unqualified diamond means natural diamond; laboratory growth and treatment must be disclosed. [16] |
Mainland China | GB/T 16552-2017 and separate institutional standards |
Scope and version matter. ISO’s catalogue records ISO 18323:2015 as reconfirmed in 2026. NGTC’s Q/NGTC-J-SZ-0001—2020 is an enterprise standard applying to that organisation and its affiliated units. Read naming and identification documents in the context of their version, adopting organisation and sales market. [15][18]
Taiwan: Clear Chinese Labelling and Accurate Product Information
Taiwan’s Commodity Labeling Act sets general requirements for information such as product names and principal components or materials. Labels must not be false or misleading, and Chinese is generally the main language, subject to the Act’s specific provisions and exceptions. See Articles 6 and 9–11 of the Commodity Labeling Act. [21]
Article 21 of the Fair Trade Act prohibits false or misleading representations about matters that may affect purchasing decisions, including quality, content, manufacturing methods and origin. These regulate product information and advertising rather than define diamond through a carbon percentage. RAGAZZA’s communication principle is to use clear, complete Chinese names identifying natural or laboratory-grown origin, with consistent descriptions, transaction documents and report information. See the Taiwan Fair Trade Commission’s explanation of Article 21. [22]
Malaysia: Trade Descriptions Include Composition and Production Methods
Sections 5–7 of Malaysia’s Trade Descriptions Act 2011 (Act 730) prohibit false or materially misleading trade descriptions, covering matters such as a product’s nature, composition and manufacturing or production methods. For diamond products, both material and growth origin need accurate description. Identifying diamond material does not replace explaining natural or laboratory-grown origin. These are general trade-description provisions, distinct from diamond-specific nomenclature standards. [23]
Hong Kong: Specific Rules for the Commercial Use of Diamond Names
Section 2 of Hong Kong’s Trade Descriptions (Definition of Diamond) Regulation, Cap. 362L, defines commercial use of “diamond” with reference to a natural mineral, cubic carbon crystal structure and scheduled physical properties. It provides an exception for combinations with words such as artificial, man-made or synthetic that clearly indicate, as a whole, that the article is not a natural diamond. Complete naming therefore matters alongside material identification. See Hong Kong Cap. 362L. [10]
6 Why Distinguish Origin Within the Same Material?
Material Definitions and Product Names Preserve Different Information
A material definition rests on composition and crystal structure. A product description also needs growth origin and treatment status. Some naming frameworks reserve the unqualified product name for natural origin. That commercial convention can coexist with the finding that an artificially grown crystal has diamond structure.
Ruby offers a useful comparison. Natural ruby and synthetic ruby both have a corundum material basis, while product names still distinguish natural formation from artificial growth. “Synthetic” describes growth origin and differs from a glass imitation. A complete name can preserve both material identity and formation history. [19]
Gemstone appearance reflects material, facets and lighting. Identification and product information establish growth origin and treatment status.
How RAGAZZA Uses These Definitions
RAGAZZA offers both natural and laboratory-grown diamonds. In educational material, we explain diamond through its chemistry and crystal structure. In product descriptions, we identify natural or laboratory-grown origin and disclose known treatments. This keeps the material explanation accurate while retaining the information buyers need to choose by origin.
The geological history of natural diamonds and the technology behind laboratory-grown diamonds can each have appeal. Naming should make the differences clear so that preferences rest on adequate information. Quality, rarity and market price require their own assessment; they cannot be inferred from the material name alone.
7 Frequently Asked Questions About the Definition of Diamond
Q Does Diamond Have to Be 100% Pure Carbon?
A Diamond can contain trace elements, lattice defects and inclusions. Identification establishes composition and diamond crystal structure. The commonly cited 99.95% carbon description is not a universal pass mark; an analysis must be understood in its measurement context rather than used as a percentage-only definition.
Q Can a Colour-Treated Natural-Origin Diamond Be Labelled Only as Natural?
A Growth origin and treatment status need to be disclosed together. Natural origin may remain an identification finding, but colour treatment and other relevant treatments must still be explained. Product naming follows the applicable framework: CIBJO, for example, uses “treated diamond” and does not accept “treated natural diamond” as the product name. [9]
Q Are Synthetic Diamonds and Laboratory-Grown Diamonds Different Materials?
A In gemmological nomenclature, both terms describe artificially grown diamond, distinct from simulants made of other materials. Accepted commercial wording varies by framework. Read the complete name and origin conclusion on the report. [7][9][18]
Q Why Include Laboratory-Grown If the Material Is Diamond?
A “Diamond” identifies the material; “laboratory-grown” identifies origin. Buyers may care about formation history as well as material. The complete name preserves both and helps meet the origin-disclosure requirements of the relevant market. [12][16]
For practical identification, read How to Tell If a Diamond Is Real. For a closer look at laboratory-grown material and reports, see Are Lab-Grown Diamonds Real Diamonds? Materials, Certification and Identification.
To explore complete product names alongside actual stones and reports, visit RAGAZZA Taipei, Kuala Lumpur, Macau or Hong Kong. Compare natural and laboratory-grown diamonds with the origin and quality information that matters to you.
Sources
Legal and standards sources reviewed on 15 October 2026. Referenced documents and versions are listed below; the article distinguishes laws, national standards and institutional documents.
