Lab Grown Diamonds 101

Natural Diamonds vs Laboratory Grown Diamonds vs Diamond simulants

There is a lot of confusion today about natural diamonds, lab-grown diamonds and diamond simulants.  People in the jewelry trade understand the difference but many consumers do not.  The following facts should eliminate any further confusion:

Lab-grown diamonds are a manufactured product produced in highly controlled laboratory conditions that reproduce similar conditions as are found in nature.  They have the same chemical composition, crystal structure and physical properties as mined diamonds and are extremely difficult to differentiate by use of a jeweler’s loupe or even a microscope.  Both are 100% carbon-based.  Natural diamonds form deep within the earth’s mantle over hundreds of millions of years.  Lab –grown diamonds are created thru new technological advancements and can usually be manufactured (depending upon their size) in 6 to 8 weeks, by one of two methods: CVD (chemical vapor deposition) or HPHT (high pressure high temperature).

Diamond simulants, which include cubic zirconia, moissanite, white topaz and colorless sapphires, are made to look like diamonds, but are composed of very different materials.  They share none of a diamond’s chemical composition or physical properties. They are not made of carbon crystals. They are non-precious. They do not possess the same hardness, durability or brilliance.  And most significantly, they can clearly be distinguished by the naked eye and sell for much lower prices.

Natural Diamonds vs Laboratory Grown Diamonds vs Diamond Simulants

NATURAL DIAMONDS: A natural diamond is 100% carbon-based and forms deep within our earth’s surface (mantel) over hundreds of millions of years. Natural diamonds maintain value over time because they possess three essential components: BEAUTY, DURABILITY & RARITY.

LABORATORY GROWN DIAMONDS: A laboratory grown diamond (LGD) is 100% carbon- based and is a manufactured (man-made) product. They are essentially the same as natural diamonds, chemically, optically and physically. LGD’s are created over a relatively short period of time (approx. four to five weeks for a 1 ct.) in highly controlled laboratory conditions, using one of two methods; Chemical vapor deposition (CVD) or high pressure/ high temperature (HPHT).

The chemical vapor deposition process consists of placing a tiny seed diamond into a plasma reactor, adding hydrogen and methane gas, and super-heating it to approximately 7000 degrees Fahrenheit causing carbon atoms to rain down over the seed. After 400 to 500 hours, a newly formed rough crystal is ready to be polished by artisans into a finely crafted diamond.

The high pressure/high temperature process consists of placing a diamond seed into a crucible. By applying extreme high pressure and heat within the crucible, a newly formed crystal is created. When the desired size is reached, the crystal is taken out of the crucible and given to an artisan to polish into a finished gem-quality diamond.

SIMULATED DIAMONDS: A simulated diamond (SD) is NOT chemically or physically similar to a natural or laboratory grown diamond. A SD simulates or appears to visually look like a diamond, but in fact, is not a diamond at all. Examples of diamond simulates are: cubic zirconia, moissanite, colorless sapphire, colorless topaz, glass and others. Both natural and laboratory grown diamonds possess a hardness of 10 on the Moes scale of hardness, as compared to diamond simulates, which are much lower on the scale. This is important as the hardness of a diamond prevents chipping, scratching and breakage. The durability of diamond simulates is not even close to that of natural or laboratory grown diamonds.

Lab-grown Diamonds are a product of today’s remarkable technological advances. They are in every way identical to mined diamonds, except they do not come from the earth. They have all the optical, physical and chemical properties of mined diamonds and are just as brilliant. No longer are higher-priced natural diamonds the only choice for engagement rings and fine jewelry. Inevitably, LGDs are the future.

The Laboratory Grown Diamond Exchange gives buyers from around the globe the ability to find what they’re looking for at the best competitive market prices. Our listings include all objective information; carat wt, shape, color and price. We do not opine on clarity as clarity is a subjective judgement call.


The most popular LGD shapes are the following:

The Round brilliant is the most popular shape, representing the largest percentage of gems sold. Due to the mechanics of its shape, the round brilliant is, generally speaking, more brilliant compared to that of fancy shapes, as the proper reflection/refraction of light, truly maximizes potential brightness.

Like the round brilliant, the Princess shape is a good choice for its flexibility in working in almost any style of ring.

The look of the Emerald shaped step cut is unique. Instead of the sparkle of a brilliant-cut, emerald shaped LGDs produce a spectacular “hall-of-mirrors” effect, with the interplay of light and dark planes.

The Pear brilliant cut is a combination of a round and a marquise shape, with a tapered point on one end. The point should line up with the apex of the rounded end and the upper and lower curves on the right and left side should form uniform, symmetrical curves.

The Radiant cut LGD is the first rectangular cut to have a complete brilliant-cut facet arrangement applied to both the crown and pavilion, creating a vibrant and lively gem. The modified rectangular shape is a bridge between a cushion and a princess cut and looks beautiful set with rounded or square cornered LGDs.

The Marquise, long and narrow, can also create the illusion of greater size; a good choice when trying to maximize that perception.

The Cushion cut LGD combines a square cut with rounded corners, much like a pillow.

The Heart shape brilliant cut LGD is a unique and unmistakable symbol of love, popular in solitaire pendants as well as rings.

Because the Oval shape is an elongated brilliant-cut, the two shapes display a similar fire, dispersion and brilliance. However, oval cut diamonds have an added advantage – their elongated shape can create the illusion of greater size.

The Asscher cut LGD is similar to the emerald cut, but in a square shape with larger step facets, a higher crown and a smaller table. This combination often produces more brilliance than the emerald cut.

Carat weight is an important question you will ask yourself when buying an LGD, because compared to all the other factors, carat weight has the greatest effect on the price and will determine the size of the LGD you buy. Depending on your budget, the answer will most likely be, “the bigger, the better”.

One carat equals 200 milligrams in weight. For LGDs under one carat, each carat is divided into 100 points – like pennies in a dollar. For example, ½ carat = 50 points. ¼ carat = 25 points.


LGD proportions refer to specific parameters within a gem such as table size, crown height and pavilion depth percentages. Table size is the size of the table facet in relation to the diameter of the LGD expressed as a percentage. This percentage is rounded to the nearest whole percent. Today, the table size of most LGDs lies somewhere between 55 and 65 percent. Too large a table unbalances an LGDs scintillation. That is, its reflection creates a flash that overpowers the refraction from other facets. Additionally, large tables reduce dispersion.

In LGDs, all the various angles and proportions are expressed in terms of their relationship to the girdle. In rounds, the standard of comparison is the average girdle diameter; this is the base against which all other percentage proportions are calculated.

Facet angles are set and measured in relation to the girdle plane, which you can imagine as a disk inserted between the crown and pavilion. A polished LGD’s proportions affect its light performance, which in turn affects its beauty and overall desirability. LGDs with correct proportions, symmetry and polish optimize their beauty, quality and value.