Synthetic and Simulated gemstones

High value gemstones are mostly unobtainable to the average person.  The desirability of these cherished pieces created a demand for identical looking imitation gemstones.  These laboratory-grown gemstones are used honestly in a wide variety of applications like fashion jewelry; however, deceitful sellers can often try to swindle even the most experienced buyer. 

There are two distinctions between synthetic and simulated gemstones based on whether they have the same properties of their natural counterpart or if they only resemble the natural gemstone.

Depending on how these replica gemstones are marketed, they can be described as either synthetic or simulated gemstones.  Violet sapphire created in a laboratory is called “synthetic violet sapphire” or when it is used to simulate violet quartz it is called “imitation amethyst.”

Synthetic (laboratory-grown) gemstones

These gemstones are identical in composition to their natural counterparts in every way; the only difference is that they are created in a laboratory. These synthetic gemstones are often labeled as “laboratory grown” or “laboratory created”, words which are more acceptable to a buyer than “synthetic”.  As synthetic gemstones can be made at any time, they are not rare and prices and quality do differ due to the different manufacturing methods.

Simulant (imitation) gemstones

Imitation gemstones that do not have the same properties as natural gemstones but resemble the natural gemstone they imitate are called simulants. A simulated gemstone can be any material that takes on the appearance of a natural gemstone.  The most popular diamond simulant is cubic zirconia which has enjoyed a two decade stronghold over other simulants.  There are a number of diamond simulants but only cubic zirconia and moissanite have commercial significance today.

Cubic zirconia is an inexpensive diamond simulant and an excellent alternative to diamond due to its high optical properties and good brilliance. Although mostly seen in its white or colorless forms, it is also available in a wide variety of colors.

Scientists only started creating moissanite fairly recently.  It is a very hard and brilliant jewel found naturally in asteroids and meteorites.  Moissanite has a hardness of 9.25, which makes it harder than any gem except diamond. To the naked eye, moissanite is virtually indistinguishable from diamond but it is more expensive in comparison to other manufactured gemstones.  Under a microscope, it can be distinguished from a diamond by the heavy double refraction on the facet edges.

Blue Sapphire and White Gold Ring

Buy this ring from ANNE MANACZYNSKI

 

The following table compares the properties of diamond with synthetic cubic zirconia and synthetic moissanite

 

Diamond

Cubic Zirconia

Moissanite

Composition

Native carbon

Zirconium oxide

Silicon carbide

Crystallography

Cubic

Cubic

Hexagonal

Refractive Index

2.417

2.15 to 2.18

2.65–2.69 (0.040)

Specific Gravity

3.52

5.40 to 5.95

3.22

Hardness (Mohs)

10

8.5

9.25

Dispersion (B–G)

0.044

0.058 to 0.066

0.104

Composite gems (assembled stones)

These gemstones are also known as doublets or triplets as they consist of two or more parts that have been joined together to create a single gemstone.  The pieces include combinations of natural, synthetic or simulant material. Colour usually derives from dyes within the layers or a single component.

In general natural material is used for the crown of the assembled gem,  inspection therefore will reveal natural inclusions and therefore look most realistic. Popular composites include ruby, sapphire and alexandrite doublets.

 

Aquamarine and Palladium Ring

Buy this ring from ANNE MANACZYNSKI

 

Production processes:
The flame fusion or Verneuil process

This is still the most common process used for gemstone synthesis due to low production costs and high crystal growth rates. Large numbers of flame fusion gemstones like rubies, sapphires and spinels are readily available. The powdered ingredients are fused together under a high temperature oxy-hydrogen flame. As the powder melts it crystallizes in successive layers. The curved growth layers are important identification features and can be observed under a 10x loupe or microscopic. Sometimes clouds of gas bubbles are visible.

Flux-melt technique

This technique is rarely used in fashion jewelry or industrial applications due to higher production costs. This technique poses the greatest threat to the gemstone trade as flux grown rubies have inclusion patterns that very closely mimic the patterns seen in natural counterparts.  By dissolving ingredients into molten fluids and crystallizing them under controlled conditions, the desired gemstone mineral is produced.

Clues to these synthetic gemstone origins are usually found on the microscopic level. Small platelets from the side of the crucible are proof of synthetic origin as are flux fingerprints that have solidified residues within the fingerprint cavities.

The hydrothermal technique

This technique is commonly used in manufacturing high quality synthetic emeralds, where the process closely mimics how many natural crystals originate from high temperature, high pressure water solutions.

The ingredients are enclosed in a partially filled, sealed container of water and heated to high temperatures.  The ingredients are dissolved and at point of cooling crystal growth is induced.

0 items found
Sort By: