Most people probably imagine diamonds first and foremost as for an engagement ring but many people also buy diamond jewelry for self-gifting, as a “reward” to themselves. You may wonder what diamonds you should select for such occasions.

Generally speaking, it is said that the higher the criteria of the “4Cs” indicating the carat weight, cut, clarity and color, “the better the diamond”. However, some of these diamonds fund conflicts or terrorist activities or may be mined or cut without respecting workers’ rights and the environment.

Diamond is a hard gemstone and the word “diamond” comes from a Greek word “Adamas” meaning “indomitable” or “unconquerable”. Therefore, the symbolism behind a diamond is that of an “eternal bond”. It also represents “purity”. To stay true to this meaning, we believe that it is important for people to select diamonds that have traceable origins and backgrounds, since they will be kept with you forever.

■Table of Contents

  1. What are the 4Cs?
  2. Conflict diamonds and the Kimberley Process Certification Scheme
  3. Human rights and environmental issues surrounding diamonds
  4. “Diamonds Sourced with Love” is ideal
  5. What brand is the best?
  6. Stories about “Diamonds Sourced with Love”
  7. A small step makes a big difference

1 What are the 4Cs?

Diamonds are generally evaluated comprehensively using the four criteria, the so-called “4Cs”, that are carat weight, color, clarity, and cut. The Gemological Institute of America (GIA) developed these criteria in the 1950s, and DeBeers’ adoption of the term in an advertisement campaign in the United States made it popular. Today, the 4Cs are the universal method of evaluating diamond quality around the world.

1 carat is defined as 200 milligrams. It is one-fifth of the weight of a US One Dollar Bill, which is equal to 1 gram. 1 carat diamonds are about 6.5 mm in diameter, but the size varies depending on the cut. If all other conditions are exactly the same, heavier diamonds are, the rarer. A survey conducted in Japan by a Japanese wedding magazine in 2019 shows that 33.3 percent of the respondents in Tokyo and the surrounding three prefectures purchased diamonds of 0.2 to 0.3 carat weight for their engagement rings and 27.7 percent of the respondents 0.3 to 0.4 carat. Thus, more than half of the respondents selected 0.2 to 0.4 carats (about 3.8 mm to 4.8 mm in diameter).

Diamond carat chart, courtesy of International Gemological Institute (IGI)
Diamond carat chart, courtesy of International Gemological Institute (IGI)

The less color it has and the more transparent the diamond is, the higher its rating according to the 4Cs. Diamonds are classified into 23 levels as color increases, starting with the highest “D” representing colorless, down to “Z” with a yellowish tint. D color diamonds are such rare that it is said that the chance of finding one is one in 20,000, which makes them expensive. Colorless diamonds (D to F) are the most popular for engagement rings and wedding rings.

Diamond color chart, courtesy of International Gemological Institute (IGI)

Clarity has 11 grades that range from “Flawless” to “I3” (heavily included), which evaluates diamonds comprehensively by observing diamonds’ inclusions and external characteristics (blemishes) as to their size, position, number and visibility. Natural diamonds are carbon crystals formed deep in the earth under high heat and pressure. Most diamonds contain impurities and other elements inside, and you can sometimes see the trigon formation of the diamond “skin” on the surface. The fewer the inclusions and blemishes, the higher the transparency and thus the higher the worth.  However, the inclusions tell a story also about the long natural creative process of the diamond and so can be seen as adding interest and a special interest to the stone – making it unique.

Diamond clarity chart, courtesy of International Gemological Institute (IGI)

Cut is the only criterion of the 4Cs that evaluates human skill. Diamond has a particularly high refractive index among minerals and reflects light well inside, making the stone appear more brilliant. The 58-facet “round brilliant cut,” which is most commonly used in engagement rings, was designed as the form that most efficiently reflects the light entering diamonds, and the cut grade in 4Cs is limited to this “round brilliant cut”. Cut comprehensively evaluates diamonds based on a diamond’s proportion (shape), symmetry and polish, and grades it according to five levels, from Excellent (highest) to Poor (lowest).

Diamond cut chart, courtesy of International Gemological Institute (IGI)

The value of diamonds traded on the international market is determined by their rarity and the 4Cs. However, some of these diamonds may be related to issues such as child labor, forced labor, violence and environmental destruction in mining and cutting processes, or “conflict diamonds” which fund weapons used in conflict zones. Knowing its 4C rating is not enough to tell us if the diamond is mined or cut responsibly with consideration for people, society, and nature.

2 Conflict diamonds and the Kimberley Process Certification Scheme

According to the United States Geological Survey, about 46% of the world’s diamonds are produced in Africa (2019). Many civil wars broke out in Africa in the 1980s and 1990s, and diamonds were one of the causes of the prolonged and escalating civil wars. Rebel groups took armed control over diamond mines, forced nearby residents to work there, and financed the buying of weapons and hiring of combatants through the diamonds mined. Such diamonds are known as “conflict diamonds” or “blood diamonds”. The movie “Blood Diamond” (2006), starring Leonardo DiCaprio, is a story about the reality of trafficking diamonds in Sierra Leone during the civil war, and drew attention internationally to the issues surrounding diamonds.

As the issue of conflict diamonds came to light, diamond-producing countries met for the first time in May 2000 in Kimberley, South Africa. On December 1st of the same year, the United Nations General Assembly unanimously adopted a resolution to support the establishment of an international diamond certification scheme. In response to this, international communities and the diamond industry as a whole set up the “Kimberley Process Certification Scheme (KPCS),” an initiative to export rough diamonds with certification that they are not conflict diamonds.

Diggers washing diamonds at a diamond mine in the Kono district, Sierra Leone (©2012 Diamonds for Peace)

However, the KPCS is not perfect and has several loopholes. Firstly, the definition of conflict is limited to the rebel groups which are trying to overthrow legitimate governments and does not cover these governments’ own financing of their armies or security forces. Secondly, the KPCS does not cover human rights issues related to miners/diggers, such as their health and working conditions, child labor, fair wages, and violence, or the environmental issues caused by the mines. Thirdly, the KPCS only applies to rough diamonds, so this transparency of mine origin can be lost with cut and polished stones that are batched together from multiple mines at the time of export.

For more information, please refer to “Conflict Diamonds”

3 Human rights and environmental issues surrounding diamonds

Many workers involved in diamond mining suffer from human rights violations such as child labor, bonded labor, forced labor, abuse, violence, and sexual violence at mining sites. These human rights violations are seen mainly in countries with unstable conditions after the civil wars, with inadequate laws and protective systems in place for diamond mining and export, or with corrupt politics. As mentioned above, the KPCS alone is unable to prevent such violations.

There are international standards related to business and human rights, such as the United Nations “Guiding Principles on Business and Human Rights” and the Organization for Economic Co-operation and Development (OECD) “Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas.” International human rights organizations, Human Rights Watch, Amnesty International and the like, call for the responsibility of each jewelry company to respect human rights in accordance with these international standards at each stage of the diamond supply chain, from mining to sales.

The good news is that the Kimberley process is still evolving and in November 2021, its members, made a formal declaration of support for the principles of responsible diamond sourcing as best practices (the so called “Frame 7”) which promotes further due diligence in terms of human rights and protection of the environment.

For more details see: 2021_kp_declaration_frame7.pdf (

The environmental destruction caused by diamond mining is serious. Forests are cut down to make diamond mines, river courses are sometimes changed, thus disrupting the balance of the ecosystem. Mining sites require that a large amount of soil be dug up during the mining process, and many sites are often abandoned without being reclaimed after diamonds are dug up. Such abandoned sites usually end up waterlogged with manmade ponds. Not only are these sites unusable as farmland, they also pose health threats as breeding grounds for mosquito lava carrying malaria and increase the risk of accident from people and animals falling into the water and drowning.

For more information, please refer to “Environment”.

An artificial pond created at a post-mining site of diamonds in Kungbor, western Liberia (©2017 Diamonds for Peace)

Recently, laboratory-grown diamonds which have the same physical characteristics as natural diamonds, have entered the market. Their marketing images of being free from human rights abuse and environmental destruction as well as being less expensive than natural ones seem to be the reason they are gaining more attention from consumers. However, considering the high environmental impact in the production process of laboratory-grown diamonds using huge amounts of electricity and the human rights issues in China, one of the main producing countries for laboratory-grown diamonds, it may not be possible to assert that laboratory-grown diamonds are fully “ethical.”

For more information, please refer to our article “Mined Diamonds vs. Laboratory-Grown Diamonds” (insert URL here).

4 “Diamonds Sourced with Love” is ideal

What kind of diamonds should consumers select? We, Diamonds for Peace (DFP), call natural diamonds which are traceable to mines (at least to the producing country) and are not associated with conflicts or terrorism, “Diamonds Sourced with Love.” We’d like to encourage you and the jewelry industry to be more aware of the various issues surrounding diamonds and to make responsible decisions for purchases.

Our ultimate goal is that all diamonds should be “Diamonds Sourced with Love”, which meet the following criteria.

  1. The Diamond is traceable from mine to consumer.
  2. The Diamond has not been used to finance conflict or terrorism in the process of its mining, cutting and manufacturing.

iii. The human rights of workers at the mine and factories where it was processed are respected.

  1. The damage to the environment is kept to a minimum in the process of mining, cutting and manufacturing.
  2. The rights of people and local communities are respected.

Unfortunately, there are few diamonds for now that meet all of the criteria mentioned above, but, when you are selecting a diamond, we would like you to ask the sales person whether they have a certificate that shows the country of origin and other relevant questions as to its mining and manufacture. Even if a jewelry company/brand is certified by RJC (Responsible Jewelry Council) or another reputable organization, you should not be satisfied with the certificate itself. It is important to make an effort to find out what the certificate means by asking questions yourself.

*For more information, please refer to “Diamonds Sourced with Love Campaign”.

5 What brand is the best?

We, Diamonds for Peace, are not in a position to recommend any particular brand when consumers are looking to make a diamond jewelry purchase. However, a report released in November 2020 by Human Rights Watch (HRW), titled “Sparkling Jewels, Opaque Supply Chains: Jewelry Companies, Changing Sourcing Practices, and Covid-19” may be helpful.

The report selects 15 of the world’s leading jewelry and watch brands, and examines and rates them on their efforts to address human rights abuses and environmental issues in their supply chains. HRW conducted a similar survey in 2018 and said “Major jewelry companies are improving their sourcing of gold and diamonds, but most of them cannot assure consumers that their jewelry is untainted by human rights abuses”. No companies were ranked “excellent” at a ranking of “significant steps toward responsible sourcing.” Two companies, Tiffany & Co. and Pandora were ranked “strong”, and three, Bulgari, Signet and Cartier were ranked “moderate”.

Some jewelry brands may claim to be “ethical”, but as the above-mentioned report shows, they may not have enough proof of responsible sourcing, or the reality may be different, so please be careful not to rely on them blindly.

6 Stories about “Diamonds Sourced with Love”

We, Diamonds for Peace, collected some stories by consumers who purchased “Diamonds Sourced with Love” in following examples.

(1) Masashi (Japan)

Country/Mine of Origin: Australia/The Argyle Mine

I wanted to present to the woman I want to marry a diamond whose origin is known and assured. I checked it by myself and consulted with a shop clerk to get to know about colored diamonds. Among them, I found out that pink diamonds mined in the Argyle Mine in Australia were managed by Argyle for the market.

I made a surprise proposal to my girlfriend, with the words “I would like you to receive the diamond I looked for desperately.”

(2) TK (Japan)

Country/Mine of Origin: Australia/The Argyle Mine

I bought a pair of diamond earrings for my birthday. Because I had learned about the issues with some diamonds, I wanted to wear diamonds that had no such issues. Also, because diamonds were expensive and I would wear them for a long time, I wanted to know where they came from. I love to wear them at any place and any time for their minimal design. I hope to cherish and leave them to my daughter, along with the story behind the purchase of the earrings.

(3) Marie (Japan)

Country/Mine of Origin: Kingdom of Lesotho/The Liqhobong Mine

I wanted to choose a wedding ring which had a positive environmental and social impact. I looked at the websites of high brands to see what kind of initiatives they were taking. I found out a little about the mention of the Kimberley Process Certification Scheme on their websites, but I couldn’t find anything convincing. In the meantime, a certain brand that deals with ethical jewelry detailed the information I needed. As for the yellow diamond I chose, I was able to identify its mine and its polishing factory. I also found out that its miners received a fair portion of the proceeds, and that the polishing factory was ISO certified, and was environmentally friendly. My husband to be knew that I was interested in ethical jewelry and left the choice to me. I’m satisfied with my choice and wear it with confidence.

For more information, please refer to “Diamonds Sourced with Love Campaign”

7 A small step makes a big difference

You may now think that selecting diamonds is surprisingly difficult. The issues surrounding diamonds are deep-rooted ones, and not many companies/organizations within the industry make true efforts as yet towards fully responsible sourcing. However, shopping and consumption are like voting, enabling you to show “what kind of society you want to have.” Depending on what kind of diamonds you buy, the environment surrounding the diamond industry can become better or worse. You can try to ask at the stores about the origin of the diamond and the conditions for the workers at the mines and in the factories or search for “#ethicaldiamond” or “#ethicaljewelry” on SNS. Your small step will surely lead to a big difference in the future.