Diamonds

Simulated vs. Synthetic vs. Natural Diamonds

Simulated Diamonds
A diamond simulant is any material which is not diamond or synthetic diamond, but which simulates a diamond’s
appearance and is used in its place. Common diamond stimulants include synthetic cubic zirconia (CZ),
gadolinium gallium garnet (GGG), synthetic spinel, synthetic moissanite and yttrium aluminum garnet (YAG).
These are also referred to as diamond substitutes.

Synthetic Diamonds
On the other hand, a synthetic diamond is a man-made diamond, produced either by subjecting carbon-bearing
material such as graphite to high temperature and pressure or by the chemical vapor deposition (CVD) method.
In 1954, General Electric announced it had combined high temperature and high pressure to replicate the
conditions 120 miles beneath the earth’s surface. It began transforming carbon into the hardest substance
known to man – the successful synthesis of diamonds.

A synthetic diamond is a laboratory-grown material with essentially the same physical, chemical and optical
properties as its natural counterpart. Colors range from dark green, light green, red, yellow or blue to colorless.
Millions of carats of industrial-quality synthetic diamonds are now manufactured annually using high pressure
techniques; and gem-quality synthetic diamonds have been produced experimentally by De Beers Diamond
Research Laboratories, General Electric, Sumitomo Electric Company in Japan and by the Russians.

Natural Diamonds
Diamonds are minerals composed essentially of carbon crystallized at extreme high temperatures and pressures.
In nature, diamonds were formed at 150 to 200 kilometers (93 to 124 miles) or more below the earth’s surface.
Diamonds are not only the hardest substance known to man; they have certain optical characteristics that
are unique. They have a refractive index of 2.417, dispersion of 0.044, a specific gravity of 3.52, and their
luster is adamantine. A diamond forms in the cubic, or isometric, crystal system and has four directions of
perfect octahedral cleavage, and shows a step like fracture surface. Its color ranges from yellow, brown,
gray, orange, green, blue, white, black, purple, pink and, extremely rarely, to red. Transparent and
near-colorless is a desirable color, a diamond is a highly valued gemstone; poorly colored and heavily included
single crystals are used for a wide variety of industrial purposes.