Cremated Ashes to Diamonds: The Carbon Journey

One of the most common questions that we get here at Eterneva involves the science behind our lab-grown diamonds. Is there enough carbon in cremated ashes to create a diamond? The short answer: yes. Human beings are carbon-based lifeforms, and 18.5% of our mass is made up of carbon.

While some of that carbon is transformed into carbon dioxide during cremation, 1-4% still exists in the ashes and fragments of bones that remain after the process, yielding an average of 2.5 to 8.5 mg of carbon. Since we only need 1 mg of carbon to grow a diamond, there is more than enough to facilitate the growth process of multiple diamonds with only a half cup of ashes.

In this article, we’re going to take a closer look at the science behind extracting carbon from cremated remains and transforming it into lab-grown diamonds in order to provide clarity regarding the process and confidence to those who want to memorialize their loved ones through this journey.

How much carbon exists in the human body?

There are a total of 92 unique elements found in the human body, 11 of which are found in quantities above 0.01%. Of those 11 primary elements, there are four key substances that make up 96.2% of the average person, including:

·  Oxygen (O): 65%

·  Carbon (C): 18.5%

·  Hydrogen (H): 9.5%

·  Nitrogen (N): 3.2%

Carbon is a fundamental building block of life, plays a major part in the formation of DNA, and can be found throughout the body in various bonded compounds that form our bones, muscle tissue, major organs, skin, and hair.

During the cremation process, a body is exposed to temperatures ranging from 1,400°F to 1,800°F, transforming much of the solid matter to gasses through combustion. One of these gasses is carbon dioxide, which takes with it a large percentage of the body’s carbon. However, after cremation, bone fragments and other base elements remain, which are then reduced to the powdered ashes that are returned to the family.

Bones consist mainly of water, carbon-based tissues in the form of protein collagen, and other minerals. Cremation burns off the water and the majority of the living tissue, but the remaining minerals, which include a type of calcium phosphate known as hydroxyapatite, contain calcium carbonate—a source of carbon. So, while the amount of remaining Carbon is greatly reduced from 18.5% to roughly 1-4%, there is still a significant amount present in the material left behind after cremation.

Elements found in the human body periodic table.

With this material, scientists have been able to use carbon-dating on cremated remains since 2001, and the existence of residual carbonates in cremated remains was later validated by a study conducted in 2009 by the Department of Biology and Department of Anthropology at Ludwig-Maximilian-University Munich.

In the 2009 study, researchers collected cremated remains for analysis and cremated the tibia bone of a cow at temperatures ranging from 212°F to 1,832°F to compare the reduction of the remaining carbonates as the temperature was increased. Each piece of bone used in the study was held at the control temperature for one and a half hours and then tested to determine how its elemental composition was affected by the increasing cremation temperature.

Researchers found that there were residual carbonates remaining in the test samples and cremated remains all the way up to the maximum temperature above 1,832°F, confirming that some amount of carbon would survive even the highest cremation temperatures. 

“There are residual Carbonates all the way up to the maximum cremation legal temperatures above 1,800°F.” - Forensic Science International

Is There Enough Carbon In Cremated Ashes to Make a Diamond?

Carbon testing is a standard practice used for many different purposes in a variety of industries. The most commonly known type of carbon testing is known as carbon dating, used by scientists to determine the age of organic matter through the relative proportions of carbon isotopes contained within it.

Another kind of carbon testing, known as total carbon analysis (TC), is used in common industries like pharmaceuticals, microelectronics, oil and gas, and forensics. Total carbon analysis utilizes scientific methods to test specifically for both organic and inorganic carbon 

A sample is placed in an oxygen-rich controlled environment and combusted (burned) with a quartz heating element, allowing testing to proceed without adding any extra fuels or additives that could contaminate the testing sample. After combustion in the controlled chamber, carbon combines with oxygen to create carbon dioxide, which is then analyzed with an infrared detector to determine the quantity of Carbon in the sample.

Calcium Carbonate molecule alongside a Carbon Dioxide molecule.

Eterneva used this same TC technique on samples of cremated ashes, hair, and even aquamation (eco-friendly cremation method) ashes to determine the range of carbon percentage we can expect from each. All testing was performed on controlled samples at TDI-Brooks International’s B&B Laboratories, a leader in total carbon testing. These were the results:

Total carbon testing results of different samples.

Once the carbon levels of the ashes have been determined and are sufficient, the scientists at Eterneva can begin the process of transforming the carbon into a diamond.

Reduction of Carbonates to Pure Carbon

While carbon exists in the molecular form of a carbonate compound, carbonates must first be decomposed using a high heat reduction process to purify the cremated remains into a form of carbon graphite that can be used to grow a diamond. This is achieved in a two-part process set in an extremely high-temperature, low-oxygen controlled environment.

Carbon graphite powder being poured.

This complex method requires highly specialized equipment and high-level expertise but is capable of reducing organic and inorganic materials containing carbonates and free-form carbon to crystalline graphite powder. First, gasses are used to separate impurities in the carbonates, then the remaining graphite is heated to more than 4892 °C, causing more impurities with low boiling points to become vaporized and removed. This process results in graphite (pure carbon) that is more than 99.995% pure and ready to use.

Growing Diamonds from Carbon

The use of High Pressure High Temperature (HPHT) technology to grow diamonds in a lab originated in the 1950s and was pioneered in the United States by General Electric. While the technology’s origins were centered on industrial applications, the capability to grow jewelry-grade diamonds has advanced greatly in recent years. Since the early 1990s, lab-grown diamonds have been produced with increasing size and quality to the point where they are no longer graded any differently than natural diamonds, and provide a comparable alternative to their mined counterparts.

In general, HPHT growth begins with recreating the temperatures, pressures, and conditions similar to those that occur in the mantle of the earth during natural diamond growth. Diamonds typically form at pressures of 5.5–8.0 GPa (roughly the weight of a commercial jet plane balanced on a fingertip!) and temperatures of 1,800–2,500°F, deep within the earth. 

To mimic this, HPHT diamond growth involves placing the carbon graphite powder into a growth cell and exposing it to similarly immense pressures and temperatures. The HPHT growth cell is made up of a metal alloy, which helps to facilitate diamond growth at a lower temperature than is required in nature. It also includes a small diamond seed the size of a grain of sand that functions as the formation site where the carbon can attach and begin its growth into a full diamond.

Memorial diamond.

A memorial diamond is a mix of personal carbon extracted from ashes and generic carbon that crystalizes around a tiny diamond seed to form a beautiful diamond. Both the personal carbon derived from a person’s cremated ashes and the generic carbon undergo the same HPHT process described above.

Due to the existence of minuscule impurities that tend to exist in carbon from cremated ashes, even after purification, which can affect the clarity and growth of the diamond, the personal carbon is blended with additional generic carbon. Personal carbon makes up 10-15% of the carbon used to create the diamond, But by introducing additional generic carbon, the HPHT technology is able to grow a diamond of exquisite quality, brilliance, and depth, while still encompassing the remarkable and unique life of the loved one encompassed by it.

At Eterneva, we recognize carbon for the incredible material it is—one of the building blocks of Earth and a fundamental substance in our universe. It is the chemical backbone of organic life on Earth, a cosmically connective element that can be found in stars, planets, the ocean, and our atmosphere. It is in our loved ones and in ourselves, and it carries on after we have passed.

To use it to create a beautiful memorial diamond can be a transformative and powerful process, reminding us of our connections, our memories, and the cosmic cycle of our lives.