A Guide to Colored Stones

A Guide to Colored Stones
Colored gemstones have been revered for centuries, even before the field of gemology was invented.  They were tumble, carved, polished, and faceted.  Properties like color saturation and clarity characteristics are important aspects to consider when shopping for a colored gemstone.

Natural VRS Treated : Natural color is highly desired because in todays world these stones are exceedingly rare.  Three things must coincide perfectly to accomplish an amazing natural color: chemistry, formation conditions, and time.  These three factors combine to create some of the most beautiful colors naturally occurring on Earth.  Some gemstones however are treated to help make a stone more appealing.  Some treatments include:

• Heat:  Heat can often enhance color and can be administered via human intervention. It can affect clarity characteristics and create uniform color. Combining heat with certain elements can influence color and finish what nature had started but ran out of resources to complete.  
• Fracture Filling: Or oiling.  There are several different types and methods used but the result is effectively the same.  In some stones however, oiling is accepted and some not as much greatly effecting the price
• Laser Drilling:  Yes a common diamond treatment has been used in colored stones to improve clarity characteristics.  Though these are not as commonly seen it does occur in the marketplace.
• Bleaching:  Bleaching is common in certain gemstones like jade or pearls and certainly effects value
• Surface Coating:  Coating the surface of a stone has been occurring for many years.  We see this in stones like "mystic" topaz commonly coated on the outside however other stones can be coated as well
• Dying:  Dying is commonly performed on certain gemstones to make them a more vibrant color and greatly effects the value of a stone
• HPHT: Mostly diamonds can be subject to this treatment. HPHT short for High Pressure High Temperature means just what it says subjecting the stone to high heat and pressure at the same time.
• Impregnation:  occurs in microcrystalline gemstones like jade or turquoise mostly to give them a more intense color look and a higher luster type finish 
• Irradiation:  is done to improve color or change the color of a gemstone
• Lattice Diffusion:  is done to infuse more color or color at all into a gemstone

A natural untreated gemstone that was not subject to any of these treatments will always be more valuable than a treated.  That being said treatments can make a gemstone look amazing at a fraction of the cost.  Knowing which treatments are acceptable is tricky and we are happy to help you navigate the world of gemstones!

Determining if a gem has been treated takes a careful eye to survey inclusions. With Velvet Box Society each piece has been evaluated to satisfaction by our trained Graduate Gemologist staff.  Often times we will additionally accompany our pieces with a report from a major laboratory
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Another important factor to value gemstones is:
Origin: Origin significantly contributes to the value of a stone for a few reasons.  Firstly origin became a significant factor because certain areas of the planet are better incubators for certain gems to form and because this is the case certain areas historically have produced some of the top gemstones from that category gem and are hence known as the best stone in the world.  Origin is difficult to assess by observation alone and usually is determined by the American Gemological Laboratories (AGL) or the Gemological Institute of America (GIA) or other similar laboratory.  You can read more about the different laboratories in our educational section on gemstones.
  

Synthetics:
Synthetic gemstones have the same physical and chemical properties as their natural counterparts, these however, are grown in a laboratory instead of in the earth. Synthetics are dramatically less valuable than natural gemstones of the same size, color, and cut because they were not formed over a significant amount of time and in a laboratory.  Hence synthetic gemstones are not rare. Synthetics tend to be very saturated and uniform in color and can be appealing for their price and overall look.

Assembled Stones: 
Assembled stones such as doublets or triplets can look like amazing gemstones and even test partially like their natural counterparts however their color is pulled from two or more stones being fused together. 

Grading:
​All our pieces are evaluated and graded by our professionally trained staff including GIA Graduate Gemologists. Mountings prohibit full and accurate observation of gem quality and weight, all data pertaining to mounted gems can be considered as approximate unless accompanied by an independent laboratory report (GIA, AGL, Mason Kay or others).

If you need assistance in evaluating your colored stones, have questions about ours, or have interest in learning more simply contact us!

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