Lab Grown Diamonds Stone Guide


Lab grown diamonds (also called man-made diamonds and lab-created diamonds) are more beautiful, ethical and affordable than anything we will get out of the earth. We're replicating the earth's natural process by crystallizing carbon into brilliant diamonds that are chemically, optically and physically identical to earth-mined diamonds, but are priced up to 40% less, and free of any environmental or humanitarian concerns.

Think of this as making ice in your freezer versus getting it from a glacier; both are ice regardless of the origin.

At Roselle Jewelry, we offer one of the largest selections of Type IIa grown diamonds. These are the purest form of diamond, making them brighter and harder than 98% of earth-mined diamonds. In the past, Type IIa diamonds have only been available to celebrities and royalty due to their rarity and steep price, however, all Roselle Jewelry laboratory-grown diamonds are Type IIA. 



How Are Lab-Created Diamonds Made?

Each laboratory-created diamond is grown by placing a diamond ‘seed’ into a chamber of heat and pressure. This chamber mimics the natural growing process. Crystallization occurs allowing the lab-grown diamond to mature within six to ten weeks. It is then cut, polished and graded by the same world-renowned labs that certify earth-mined diamonds. The two following techniques are most commonly used by laboratories:

Source : GIA


Chemical Vapor Deposition, or CVD, is a process used to create gem-grade diamonds as well as optics and semiconductors. The CVD process uses ultra-pure carbon-rich gasses in a controlled chamber. Carbon-based gasses, such as methane, are heated until they break apart allowing the carbon atoms within the gas to separate. These tiny carbon atoms fall onto a diamond substrate and build up layers resulting in a rough diamond crystal. This process takes between six to ten weeks and yields gem-grade Type IIa diamonds.

In recent years, CVD research has gained popularity and now modified versions of CVD are being used. These processes differ in the means by which chemical reactions are initiated. Some of these variations include:

  • Low-pressure CVD (LPCVD)
  • Ultrahigh vacuum CVD (UHVCVD)
  • Plasma-enhanced chemical vapor deposition (PECVD)
  • Microwave Plasma Vapor Deposition (MPCVD)

lab grown diamond growing from a seed



High-Pressure High-Temperature, or HPHT, recreates a diamond's natural growing environment found deep within the Earth. The machines used have the ability to build up the pressure of almost 60,000 atmospheres and temperature of 2,500 degrees Celsius.

The growth cell contains all the elements needed to grow a diamond, including a seed, highly refined graphite and a catalyst mixture consisting of metals and powders. The cell is placed in the center of the HPHT chamber. Consistent temperatures reaching 1,300 degrees Celsius and more than 50,000 atmospheres of pressure are applied. The catalysts inside the cell are the first to react to the added heat and pressure and change from solid to molten form.

The molten catalyst solution causes the graphite within the cell to dissolve. Once all the required conditions are met, the cooling process begins. This process takes place over several days and allows the carbon atoms to build upon the seed. The cell is removed from the HPHT machine once the growth cycle is complete. The new rough diamond is extracted and cleaned in preparation for final cutting and polishing.

The entire HPHT growing process requires an incredibly controlled environment to produce a gem-quality diamond. Any shift or change during growth can cause the diamond to stop growing or can create inclusions that result in unusable diamonds. Every diamond must complete the entire growth cycle before the machine can be opened. It is only after the HPHT chamber is opened that we can see the finished rough diamond and its color, clarity, and size.

Within the HPHT process, there are three primary tools used to supply the pressure and temperature necessary to produce lab-created diamonds. These are:

  1. Bars Press - The Bars Press is the most effective tool used for producing gem-quality diamonds. It uses a combination of inner and outer anvils to apply hydraulic pressure to the growth cell.
  2. Belt Press - The Belt Press is the founding technology behind growing diamonds. It can be large and produce several diamonds in only one cycle by using two large anvils that press together to create the necessary pressure. It is capable of producing gem-quality diamonds but is most commonly used to produce diamonds and diamond powder for industrial purposes.
  3. Cubic Press - A Cubic Press can be large in size and uses six separate anvils to create the necessary pressure for diamond crystal growth. It is also used to create diamond powder for industrial purposes.



Lab Grown Diamond Benefits



Our collection of lab-created diamonds are available up to IF in clarity, D in color, Ideal in cut, and up to 10 carats in size. They come in a variety of shapes including round, rose, emerald, cushion, oval, oval rose, heart, princess, trillion, and radiant. Colors include white, yellow, blue, pink, and green. 



Unlike other retailers, every Rooselle Jewelry lab-created diamond is Type IIa, the purest form of diamond. They are harder and more brilliant than Type Ia diamonds. Only 2% of earth-mined diamonds are of this quality.

Furthermore, each diamond is graded and certified by the same leading independent gemological labs that are used to grade earth-mined diamonds.



Lab-created diamonds cost up-to 40% less than their mined diamond equivalents. Buyers beware: keep an eye out for "grown diamonds" sold for a few hundred dollars per carat. If the deal seems too good to be true, it probably is. Only diamond simulants fall in this price range.



Every lab-created diamond from Roselle Jewelry is guaranteed conflict-free and sourced from first world countries where they are treated and cut in a controlled lab environment.

Unlike earth-mined diamonds, our man-made diamonds are created without negatively harming native communities, society or the Earth.

According to the 2014 Frost & Sullivan report"lab grown diamonds are seven times less impactful to the environment than mined diamonds, use significantly less resources and emit a fraction of the air pollution.” 

We'll let the numbers speak for themselves:


The mining of earth-mined diamonds results in hundreds of hectares of soil being disturbed (approximately 0.00091 hectares per carat), excessive carbon emissions and other greenhouse gas emissions that lead to deteriorated air quality and pollution. Additionally, approximately 126 gallons of water are used for every 1.0 carat diamond mined.


The amount of land disturbed in the creation of a laboratory-grown diamond equates to 0.00000071 hectares per carat. The use of water is also minimal, with approximately 18.5 liters used in the creation of a 1.0 carat laboratory-grown diamond.

Source: Frost & Sullivan - Environmental Impact Analysis

Guaranteed Conflict-Free No Yes
Hardness (MOHS) 10 10
SP3 Carbon Diamond Bonds (%) 100% 100%
Internal Crystal Structure Face-Centered Cubic Face-Centered Cubic
Hardness Comparable 2.42 2.42
颜色 Various Grades K to D grades
Price $$$$$ $$$
切割 Poor to Ideal Very Good to Ideal


Roselle Jewelry has established strong partnerships with the world's most scientifically advanced diamond growers and cutters, who share our core values, to offer our customers the largest selection of exceptional grown diamonds that are affordably priced and guaranteed conflict-free. 

In 2016, Roselle Jewelry laboratories grew the largest Grown-in-the-Hong Kong Diamond at 6.28 carats, now available for purchase online.



What Colors Are Available?



A pure carbon diamond with no impurities will grade as a colorless diamond. However, the majority of both mined and lab-created diamonds contain impurities, most of which are nitrogen. The nitrogen atoms within the diamond lattice create the yellow tint. In cases of fancy colored diamonds, a pure yellow color is created. Nearly all diamonds, both mined and lab-created, start out as yellow diamonds.

Over the span of millions of years and exposure to pressure and heat, mined diamonds split the nitrogen atoms within their lattice rendering the nitrogen atoms ability to produce yellow light. The splitting of the nitrogen atoms is what gives the diamond its ability to shine white.

In the case of lab-created diamonds, we don’t have millions of years to convert a yellow diamond to white, however, the ability to grow the diamond with little or no nitrogen produces the same result.

Growth Time

Growing a white diamond requires an incredibly controlled environment. The heat and pressure must remain consistent throughout the entire growing process. Any fluctuation or change within the growth cell can cause the diamond to stop growing or can create heavy inclusions.

Extracting the nitrogen and boron from the growth cell to remove the color from the diamond lattice also causes the diamond to grow slower. White diamonds typically take up to two weeks or longer to grow a 1.0 carat stone.

It is the extended growth time, the need to extract certain elements from the growth cell and the demand to keep the heat and pressure consistent that makes growing a white diamond difficult, thus contributing to their limited availability.

Price Comparison

Unlike earth-mined diamonds, lab-created diamonds are very limited in supply. The process used to create a white diamonds is also the most time consuming and temperamental. Given that white earth-mined diamonds are in abundance and white lab-created are in limited supply, the cost ends up being very comparable. A typical 1.0 carat lab-created diamond will range from US$5,600 to US$10,000. White lab-created diamonds are priced identically to mined diamonds using the cut, carat size, color and clarity to determine their individual worth.

Available Shapes

White diamonds yield a square-ish rough. This allows the most popular shapes to be produced: round, princess, asscher, cushion and emerald. These shapes compliment the diamond rough and in return give the highest yields. Elongated shapes like oval, marquise and pear typically aren’t produced because of their need for a more elongated rough.

The Cut

All lab-created white diamonds offered by Roselle Jewelry are hand cut. Every diamond comes with individual grading from either the IGI or GCal and shows their cut grade on the grading report. Every diamond is cut to maximize brilliance and color.

The Clarity

The clarity of a lab-created white diamond is evaluated the same as an earth-mined diamond, typically ranging from IF to SI2. All grading is done by either IGI or GCal and is included with every Lab-Created Diamond offered by Roselle Jewelry.



Roselle Jewelry’s yellow lab-created diamonds are optically, chemically and physically identical to yellow earth-mined diamonds, but are offered free of conflict and on average 10% of the cost. They are available in a color range from fancy yellow to fancy vivid yellow, in sizes up to 2.0 carats and a variety of shapes.

Both mined and lab-created yellow diamonds get their color from nitrogen. While diamonds are made up of carbon, impurities within the stone exist. It is the introduction of these impurities, in this case nitrogen, that will ultimately give the diamond its yellow color. As a diamond grows, nitrogen atoms will sometimes replace a carbon atom within the diamond's lattice structure. Once light enters the diamond, the nitrogen will reflect back yellow light.

By controlling the amount of nitrogen during the diamond's growing process, the color of the finished diamond can be selected. The more nitrogen in a diamond the yellower it will be. Too much nitrogen and the diamond will start to appear brown. “Getters” are used during the growing process to capture excess nitrogen within the growth cell. By using getters, we can grow yellow diamonds with the most desirable gem-quality colors.

Many lab-created diamonds are offered in yellow and orange/yellow colors. A lab-created diamond gets its orange color from the solvents used during the growing process. These diamonds are grown in a metal molten solution. The orange comes from solvent trapped in the diamond lattice itself during the growing cycle. These solvents, combined with the nitrogen trapped in the diamond's lattice structure, give the diamond its orange/yellow color.

Deciding on which color of yellow or orange/yellow diamond to buy is purely a personal choice. The ranges we provide fall between the most commonly grown and purchased colors.

Growth Time

It takes five to six days for one cycle in the growth machine to produce enough rough to cut a 1.0 to 2.0 carat finished yellow diamond. The nitrogen left in during the growing process that gives a yellow diamond its color actually helps the diamond grow faster than any other color.

Price Comparison

Fancy yellow colored diamonds are fairly rare in nature. Yellow lab-created diamonds cost about 75% less than their mined equivalents. Lab-created yellow diamonds are the most abundant because they are the easiest of the colors to grow. As a result, they are also the least expensive. Lab-created yellow diamonds range in price from US$3,000 to US$5,000 per carat. Earth-mined yellow diamonds can cost anywhere from US$10,000 to US$50,000.

Available Shapes

The majority of yellow diamond roughs grow in a truncated octahedral shape. Square shapes, like radiant, princess, cushion, asscher and emerald, are typically used to yield the most from the rough. Round shaped diamonds are also available. Due to the square nature of the yellow rough, elongated shapes like pear, oval and marquise are not typically produced.



Blue lab-created diamonds are optically, chemically and physically identical to blue earth-mined diamonds and are offered free of conflict and about 10% of the cost. They are typically offered in sizes smaller than 1.50 carats and come in a color range of fancy light blue to fancy intense blue.

Both mined and lab-created blue diamonds get their color from boron. While diamonds are made up of carbon, impurities within the stone exist. It is the introduction of these impurities, in this case boron, that will ultimately give the diamond its blue color. As a diamond grows, controlled amounts of boron are introduced into the growth cell which then become trapped in the diamond's lattice structure. Controlling the amount of boron in the growth cell allows the finished color to also be controlled. Once light enters the diamond, the boron will reflect back blue light.

Growth Time

It takes seven to ten days for one cycle in the growth machine to produce enough rough for a finished blue diamond up to 1.0 carat in size. The boron introduced during the growing process that gives a blue diamond its color actually helps the diamond grow quicker than a white diamond. Nonetheless, it will still grow slower than a yellow diamond.

Price Comparison

Mined blue diamonds are incredibly rare in nature and can sell for anywhere between US$200,000 to US$500,000 per carat. A lab-created blue diamond costs about 10% of what a mined diamond costs. Most blue lab-created diamonds range from US$7,000 to US$12,000 per carat. Blue lab-created diamonds in fancy blue colors are the most expensive out of all the fancy colored diamonds due to the time and care needed to achieve the most desirable colors.

Available Shapes

The majority of blue diamond roughs grow in a hexa-cubic shape. Round and cut corner shapes like radiant, cushion, asscher and emerald are typically used to yield the most from the rough. Due to the hexa-cubic nature of the blue rough, princess cuts and elongated shapes like pear, oval and marquise are not typically produced.



Roselle Jewelry’s pink lab-created diamonds are optically, chemically and physically identical to pink earth-mined diamonds but are offered free of conflict and about 5% of the cost. They are typically readily available in sizes below 2.0 carats and range in color from fancy pink to fancy deep pink.

Unlike white, blue and yellow lab-created diamonds, which get their color during the growing process, pink diamonds get their color from a post-growth treatment process referred to as irradiation and annealing.

Certain lighter yellow diamonds are most commonly used to create pinks. By showering the diamond with electrons and neutrons (irradiation), we can alter the diamond's crystal lattice structure and create a new colored center. During the second step, annealing, the stone is heated to help smooth out the alterations created from the irradiation and helps achieve the diamond's finished color.

Additional colors like purple, red and green are available and are produced post treatment using the same process as pinks. The color created during the treatment process is permanent and secure under normal wear and tear conditions. In the event of setting, repairing or servicing a color treated diamond, care should be taken when being exposed to high temperatures like a jeweler’s torch. Exposure to extreme temperatures may cause color discrepancies

Price Comparison

Mined pink diamonds are the rarest in the world. The majority of pink diamonds come from Australia. The extreme limited availability puts the cost of these pink diamonds between US$56,000 to US$150,000 per carat. A treated pink lab-created diamond costs between US$5,000 and US$10,000 per carat. The price per carat weighs heavily on the color of the diamond itself. On average, a pink lab-created diamond is about 5% the cost of a pink mined diamond.

Available Shapes

The large majority of lab-created pink diamonds will be finished or shaped in the same manner as yellow grown diamonds. A lab-created pink diamond starts as a yellow grown diamond. A grown yellow diamond's rough has a truncated octahedral shape. Square shapes like radiant, princess, cushion, asscher and emerald are typically used to yield the most from the rough. Round shape diamonds are also available. Due to the square nature of the pink rough, elongated shapes like pear, oval and marquise are not typically produced.

The Clarity

The clarity of a pink diamond is dependent upon its color. Pink colors that are fuller in saturation or have more of the pink color in them will allow for a lower clarity while a soft or light pink may require a higher clarity. In any case, as long as the diamond's inclusions are not visible to the naked eye (eye clean), you should be safe. Clarity will affect the price, so in many cases, buying a diamond that is eye clean over one with a higher clarity grade will not only save you money, but it will look just as good when being viewed in normal conditions.