Ass #16-Lab Grown Diamonds

Diamonds grown in a laboratory using Chemical Vapor Deposition (CVD) method.

Diamonds grown in a laboratory using High Pressure/High Temperature (HPHT) method.

A gemological technique used to observe inclusions and other characteristics of a diamond under a microscope.

Distortion or stress in the diamond's crystal structure, observable as interference colors.

Diamonds emitting light when exposed to UV radiation.

Device used for identifying growth sectors and interruptions in CVD diamonds using fluorescence.

The process from diamond growth to retail sale, similar to mined diamonds.

U.S. Federal Trade Commission guidelines for jewelry marketing practices.

Lab-grown diamonds containing isolated nitrogen, appearing yellow.

Colorless lab-grown diamonds, with very pure components.

Elements (like aluminum and titanium) that trap nitrogen and produce colorless diamonds.

A specific internal growth pattern in HPHT diamonds, related to their crystal structure.

Observing diamonds' response to ultraviolet light. Some diamonds fluoresce.

Distinctive growth patterns in colored lab-grown diamonds. Visible under magnification.

Inclusions of metal from the growth process visible in lab-grown diamonds.

CVD diamonds are grown in a laboratory by depositing carbon atoms layer by layer onto a substrate in a heated vacuum chamber. Gases like methane and hydrogen are used as the carbon source, and a microwave plasma provides energy to break down the gas molecules.

A substrate, typically a pre-existing diamond crystal, serves as a base for new diamond growth in the CVD process. This substrate can be natural or lab-grown.

CVD diamonds are mainly type IIa, often colorless or near-colorless. Adding nitrogen or oxygen to the gas mixture can speed up growth but may result in a brown color.

CVD lab-grown diamonds often resemble slabs with a square cross-section. The edges are initially covered in black graphite and require polishing to achieve a desired shape.

CVD lab-grown diamonds can be difficult to identify using standard gem-testing equipment. They typically require specialized laboratory testing for confirmation.

A plastic disk with microscopic crystals that transmit polarized light, used for observing strain in diamonds.

Two polarizers placed perpendicularly, blocking all light unless strain is present in the diamond.

Bright colors that appear under crossed polarizers due to strain in diamonds, ranging from red, pink, orange, yellow to green.

High-pressure/high-temperature lab-grown diamonds typically show subdued interference colors, indicating less strain.

The ability of a diamond to emit light when exposed to ultraviolet radiation.

The ability of a diamond to continue emitting light after the UV source is removed.

CVD diamonds form under less favorable conditions than HPHT diamonds, requiring more energy to break atomic bonds.

Diamonds are considered stable, although theoretically unstable, due to their longevity.

Diamonds are the metastable form of carbon, while graphite is the stable form.

In 1797, English chemist Smithson Tennant proved that diamonds are composed of pure, dense carbon.

In the 1800s and early 1900s, researchers tried to create diamonds but lacked the technology to succeed.

In 1941, Percy Bridgman, an American researcher, was hired by GE to advance high-pressure technology for diamond synthesis, though diamonds weren't made yet.

In 1952, William Eversole made tiny diamonds using the Chemical Vapor Deposition (CVD) method, a different approach to diamond growth.

In December 1954, GE scientists created the first batch of industrial diamonds using the High-Pressure/High-Temperature (HPHT) method. They announced their achievement in 1955.

In 1970, GE produced the first cuttable gem-quality HPHT lab-grown diamonds, weighing about 1 carat each in rough form.

During the 1990s, Sumitomo Electric Industries, GE, and De Beers produced larger, near-colorless HPHT diamonds for high-tech applications and experimental use.

In 1993, a 34.80-carat HPHT lab-grown diamond crystal was produced, taking 600 hours to grow.

By 2003, the jewelry industry began accepting lab-grown diamonds as a commercial product, with HPHT diamonds of various colors being produced.

In 2003, gem-quality lab-grown diamonds were produced for jewelry using the CVD method.