Lab-Grown Diamond Buying Guide

Chatham is proud to be the pioneer of lab-grown diamonds.

These diamonds have the same physical, chemical, and optical properties as mined gems do. We don’t “make” gems. We control the environment so that crystals can grow naturally: recreating the conditions in which gems grow in the earth.

The process of growing gem crystals in a laboratory rather than mining them is a bit like making ice in your freezer instead of finding it in a lake. You place the starter material, water, in a container, and put the container into a controlled environment: your freezer. Create the right conditions of temperature and time and ice crystals will form. The freezer ice will usually be cleaner and more perfect than lake ice because you can carefully control the environment. But it’s still ice, just like the ice that forms in nature. In a way, what we do is a sophisticated high-tech version of freezing water to form ice.

One of the benefits of lab-grown diamonds is that they have less of an impact on the environment than mined gems.

To grow colorless diamond crystals using the CVD process, methane gas is subjected to high-energy plasma radiation. Methane is CH4: it has one carbon atom and four hydrogen atoms. We use microwave energy heat to break the atomic bonds in the methane and free the carbon to float down and attach to a diamond seed, growing a diamond crystal atom by atom.

When everything goes well, it takes about 10-12 days to produce 140 carats of crystals that are 8-9 carats each. But there are still huge technical challenges that everyone who uses this growth method faces. That’s why production of diamonds using CVD is still quite limited. And like mined diamond, there is a lot of variety in color and clarity, which allows us the ability to offer an array of qualities.

Growing diamonds is challenging and expensive. The price difference between Chatham and mined diamonds of similar quality can be dramatic, especially in finer qualities. The difference generally varies from about 30% – 80% depending on the size, shape and quality of the diamond. The price difference increases substantially as the weight and quality of the diamond rises.

Environmental Impacts

Chatham has been operating alongside mined gemstones for 80 years. We have always stood behind the notion that our products are merely an alternative and not a substitute. It is up to the consumer to make their choice after weighing their options.

We have received a great number of inquiries regarding the ecological impacts made by growing diamonds, as interests rise. The truth is, very few things in the jewelry industry are inherently eco-friendly. Some just leave lighter carbon footprints than others while also doing less harm to the planet as a whole.

As stated, lab grown diamonds are grown two ways: under enormous pressures, 750,000 psi at 1300 C, or from the breakdown of Methane gas using microwave technology. In recent years, Stanford University put out a report that investigated these processes (independently from any grower) and concluded that even with all the equipment factored in (the equipment is not destroyed but reused and has a very long life) the carbon footprint of a lab grown diamond is only 20% of what is expended in natural diamond mining. If one were to remove the initial equipment construction, that footprint would easily be in the single digit percentages. The pressures are created hydraulically and easily achieved since a liquid cannot be compressed. In the case of CVD, high temperatures are reached using microwaves to excite and breakup Methane and is very similar to that used in an everyday kitchen, but on a larger scale. The difficulty in producing lab grown diamond is not in energy expended but in brainpower. The chemistry and physics are very complex while the computerization of the process is extremely delicate. Maintaining temperatures and pressures manually is impossible to do accurately and computers are relied on for this purpose. But nobody writes code ware on “how to grow a diamond;” very talented people must create it. The code ware is not shared with anyone and is a closely guarded part of the process.

Alternatively, an enormous amount of energy is consumed to extract diamond-bearing rocks from volcanic pipes. Approximately 10 tons of rock must be extracted and crushed for each carat of diamond rough found. These extractions are so immense they are visible from outer space, open pits spanning miles, all left like scars on the earth.

A diamond is a diamond.

Learn why the Federal Trade Commission (FTC) amended their definition of diamond in 2018.