Emeralds are delicate gemstones that due to its characteristics need greater care than diamonds, rubies and sapphires. But fear not, because with proper care your emerald jewellery could last for generations so, here are some tips you need to hold dear in order to achieve this.
The jewelry industry uses special terms for manufactured and look-alike gemstones: synthetic and simulant. The differences between them are subtle, but very important. Synthetic refers to a man made material with essentially the same chemical composition, crystal structure, and optical and physical properties as the natural gem material. There are also materials that simply look like natural gems. These products are called simulants or imitations, and can be either natural or man made. Substitute is an older term for the same thing.
Common imitant gem materials
Strontium titanate – this colorless manmade material became a popular diamond simulant in the 1950s. However, its dispersion (the optical property that creates fire in a faceted gemstone) is over four times greater than diamond. Strontium titanate is most often produced by the flame-fusion method and can be made in colors, such as dark red and brown, by adding certain chemicals during the growth process. Prevalence: rare.
YAG and GGG – several manmade materials have been used as diamond simulants over the years. In the 1960s, yttrium aluminum garnet (YAG) and its “cousin” gadolinium gallium garnet (GGG) joined classic simulants like glass, natural zircon, and colorless synthetic spinel. YAG and GGG are also available in a variety of colors. Prevalence: rare.
Synthetic cubic zirconia (CZ) – early diamond simulants have been almost entirely replaced in the past three decades by colorless CZ. It is made by a process called skull melting. As the material melts, the outer portion is kept cool to form a solid crust which then contains the melt. CZ can be produced in almost any color, and in darker hues, it is a convincing alternative for gems in purples, greens and other dark tones including black. Prevalence: common.
Glass – manufactured glass is an age-old gem imitation that is still used today. Since glass can be manufactured in virtually any color, this makes it a popular substitute for many gems. Although it is less brilliant, glass is used to imitate stones like amethyst, aquamarine, and peridot. It can also be made to look like natural phenomenal gems, like tiger’s eye and opal, and fused layers of glass can imitate the look of agate, malachite, or tortoise shell. Prevalence: common.
Quench crackled quartz – Natural colorless quartz can sometimes be subjected to thermal shock, known as “quench crackling.” The colorless material is first heated, and then subjected to quenching in a cold, liquid solution—such as water. The sudden contraction causes the material to develop a series of cracks that radiate throughout. Because these are surface-reaching fractures, the quartz can then be subjected to additional immersion in a dye solution, allowing the fractures to be filled with colored liquid. This makes a convincing simulant to such natural gems as emerald, ruby and sapphire, although the fractured and dyed appearance can quickly be seen under the microscope. Prevalence: occasional.
Doublet – a doublet consists of two joined segments. Prevalence: common.
Triplet – a triplet has three segments, or two segments separated by a layer of colored cement. Prevalence: common.
A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, namely synthetic turquoise and synthetic opal, additional compounds can be present.
The first commercially successful synthetic gems were created by the flame fusion process. This process involves dropping powdered chemicals through a high-temperature flame, where it melts and falls onto a rotating pedestal to produce a synthetic crystal. Today it remains the least expensive and most common way to make gems such as synthetic corundum and spinel.
Pulling emerged in the early 1900s. In this process, nutrients are melted in a crucible and the synthetic crystal grows from a seed that is dipped into the melt, and then slowly pulled away from the melt as it grows. Gems synthesized by pulling include synthetic alexandrite, chrysoberyl, corundum, and garnet.
Today some synthetic gems, such as emerald, ruby, sapphire, alexandrite, and spinel can be created through a flux-growth process. Flux is a solid material that, when melted, dissolves other materials in the same way that water dissolves sugar. As the dissolved chemical solution gradually cools, synthetic crystals form.
Growing a synthetic gem by the flux method requires patience and significant investment. Crystal growth can take up to a year, and the equipment is very expensive. But the results, especially when it comes to emerald, are well worth the time and effort.
Like the flux process, the hydrothermal growth process is slow and expensive. But it’s the only method for successfully growing synthetic quartz. This process requires heat and pressure and imitates the conditions deep in the earth that result in the formation of natural gems. Nutrients are dissolved in a water solution, and then synthetic crystals form as the solution cools.
Retrieved from: https://www.gia.edu/gem-synthetic
As a costumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. Here in this article you will find information of the most common treatments in gemstones
– a chemical used to alter / reduce a component of, or the entire color, of a porous gem. Some gemstones are bleached and then dyed, a form of “combination treatment.”
– altering a gem’s appearance by applying a coloring agent like paint to the back surfaces of gems (a treatment known as “backing”), or paint applied as a coating to all or a portion of a gemstone’s surface with the effect of altering the color.
– introducing colored dyes into porous or fractured gems to change their color. Such fractures are sometimes purposely induced by heating the gem so that an otherwise non-porous material can more readily accept the dye.
– filling surface-reaching fractures or cavities with a glass, resin, wax or oil to conceal their visibility and to improve the apparent clarity of gem materials, appearance, stability, or in extreme cases—to add to a slight amount of weight to a gem. The filling materials vary from being solids (a glass) to liquids (oils), and in most cases, they are colorless (colored filler materials could be classified as dyes).
– the exposure of a gem to high temperatures for the purpose of altering its color and/or clarity.
– Heating a diamond to high temperatures under high confining pressures to remove, or change its color.
– the surface of a porous gemstone is permeated with a polymer, wax or plastic to give it greater durability and improve its appearance.
– exposure of a gem to an artificial source of radiation to change its color. This is sometimes followed by a heat treatment to further modify the color. This second step also known as a “combination treatment.
– this involves using a narrow focused beam of laser light to burn an open channel from the surface of a diamond to reach dark inclusions. This is generally followed by the use of a chemical forced into the channel to dissolve or alter the appearance of the inclusion
Taken from https://www.gia.edu/gem-treatment