It may come as a surprise to learn that most gems on the market have been enhanced by a
manufacturing process.
The enhancing is used to bring out colors from the gem, in the same manner as cutting a gem
to enhance its appeal.
The different enhancement methods are always progressing with technology, but below is a quick
overview of a few methods used.
- Bleaching - high concentrations of caustic acid is used to bleach gems.
Typically pearls are bleached to give uniformity of color.
- Chemical Treatments and Reactions - typically considered chemical and heat processes,
by where acid baths and extreme heat are used together.
Commonly done to give uniformity of color to gems.
Care is taken with this process as gems can quickly be ruined if it is done wrong.
- Coatings - either enamel lacquer or a liquid coloring agent is used to fully change a gems color,
or to bring a gem uniformity of color.
Gems treated as such will produce their colors through reflection, not absorption of light.
- Dyes - gems such as jade, coral, opal, lapis lazuli and pearls have all been dyed through out time.
A good dye job is fine and will last many years.
A poor dye job may quickly loose its color and value.
- Foiling - this is done be setting foil within a closed bracket setting, so the foil cannot be detected.
Usually done with a solitaire gem of lower quality to make it appear of gem quality.
Mostly not likely to find this at retail.
- Glass Filling - the rough is heated to several hundred degrees and an artificial filler is
melted into cracks and gaps.
Borax, aluminium and silica are all used to do this.
This process is a bit controversial and is mainly done to corundums from the Asian countries.
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