For
centuries lapidary works (stone cutters) have been using a variety of treatments
and enhancements to make gemstone materials even more beautiful and attractive
than they are in their natural untreated state. To comply with certain
FTC guide lines and educate our customers, we have compiled a listing of
various gemstone materials and how they are commonly treated or enhanced
in the jewelry trade before being sold.
Unless
we state otherwise, you may assume that the gemstones, crystals and
minerals sold on this web site have undergone treatments common to the
material described.
Quartz
Family of gemstones and crystals: Amethyst, Citrine, Clear Quartz, Smoky
Quartz, green quartz
often
heat treated, sometimes irradiated sometimes dyed
most
often heated to clear up internal inclusions and change the general color.
For
example, Citrine is almost always heat treated amethyst or smoky quartz.
Odd
colored quartz such as dark smoky quartz or greenish quartz, is mostly
irradiated.
Chalcedony
Family of gemstones: black Onyx, blue chalcedony, Agate, Jasper, Carnelian,
Chrysoprase, Bloodstone
All
of these gemstones are also under the quartz family. Some of them are most
often dyed to obtain a different color than natural, for example the black
onyx commonly seen in jewelry is almost always dyed agate.
Chrysoprase
is a beautiful natural green material quite prized but it still can be
enhanced through the dye process.
Beryl
Family of gems: Emerald, Aquamarine
Emeralds
- oiled - done for centuries to fill cracks and make emeralds appear better
than natural, also fracture filled with green dye high tech polymers a
more permanent than oiling but still not absolutely permanent. More common
in the last decade, also heat treated to remove inclusions of rutile which
gives the stone a hazy look. It is almost impossible to purchase an all
natural emerald these days, fine untreated nearly flawless larger size
emeralds command a premium price.
Aquamarine
- almost always heat treated to bring out the beautiful blues this stone
is known for. But it can also be irradiated.
Tourmalines
- Rubellite ( ruby red ), Indicolite ( blues ), Greens, Oranges, Browns,
multi colors , clear, black
It
seems as though the majority of tourmaline gems ARE NOT treated or enhanced
to my knowledge.
My
pet peeve, is that many dealers try to sell bi-color ( two color green
and red stones or crystals ) as Watermelon tourmaline. While bi-color
tourmaline gems and crystals are indeed beautiful in their own right ,
BI-COLOR DOES NOT = WATERMELON !! Bicolor is a cut stone or natural
crystal with one part green and one part red/pink. Watermelon is always
a stone or crystal with the inner part showing red/pink and is surrounded
by green. Watermelon crystals are always sliced like a loaf of bread to
show this watermelon effect. In my opinion watermelon crystals and polished
stones are much more rare than two color gems and crystals and command
a premium price . This is why I believe that dealers want to sell bi-color
tourmalines as watermelon tourmalines, so they can get a higher price.
Other
color combinations of tourmaline also exist, like green and blue bi color
or red and orange or brown and black.
Topaz
family: Blues, peach, pink, salmon, reddish orange, bi colors, greens
Almost
all the different blue hue topaz is irradiated, there is some naturally occurring
blues but they are usually quite pale blue and not the fantastic blues
offered by most jewelry dealers. I would say that many of the peach /pinks
etc. are either irradiated and or heat treated to get the desired colors.
Also in the last few years, there have been newer ionic treatments such
that an atomic layer of material is fused to the outside skin of topaz
and other some gemstones to alter the color. We have seen green topaz with
this fusion treatment.
Corundum,
Sapphires and Ruby
Almost
all ruby and sapphires are at least heat treated prior to sale to the public.
In the last few years it has been detected that rubies have been also fracture
filled with dyed high tech polymers and has caused quite a stir in the
trade as it was not generally known in the business. Like emeralds all
natural non treated/filled rubies command a premium price. It is quite
common for ruby and sapphire to undergo heating to get rid of rutile inclusions
which cause a hazy look to the stones. You may not know this , but rutile
inclusions also cause a cat's eye effect in many gemstones including ruby,
sapphire, tourmaline, quartz, and kunzite among many other gem varieties.
For the rutile to cause a cat's eye effect it must be concentrated
in close parallel bundles along one axis of the crystal/gemstone. Other
wise the random rutile inclusions just cause haziness.
Diamonds
Mostly
diamonds are just cut and polished, but colored diamonds such as greens
and blues, yellows, and pinks and reds, are quite rare in nature and so
many of the colors offered in the market have been irradiated and heat
treated to obtain the desired colors. Two other things are done to increase
the beauty of naturally flawed diamonds, one is fracture filling with high
tech polymers, and the second is using a laser to drill micro holes to
get rid of black spots in the middle of diamonds. Both processes must be
disclosed to the consumer prior to the sale.
Howlite
Natural
howlite is generally a white body with gray streaks spider webbing through
the material. It is a beautiful natural material and is easy to carve in
to any shape. Howlite is listed here because it seems the number one use
of this material is to make simulated turquoise. Howlite readily takes
dye and can be made to resemble many other gemstones beside turquoise,
like lapis and others. The seller should always tell you that you are buying
a simulated item to be fair. It is not the worst thing in the world to
buy a simulated article, some times all natural items are very pricey and
the simulated materials might be the only thing that fits in your budget,
but you should know that you aren't buying a 10 inch tall turquoise Buddha
statue for $50.00 when in fact you are buying a dyed howlite statue that
looks like turquoise. Always remember one universal truth, if something
seems too good to be true, it's most often not true.
Jade
- Jadeite - Nephrite
There
are two varieties of jade the more common is nephrite, and the more valuable
is called jadeite. In the west these are the only two materials factually
and accurately called
jade. In parts of Asia and China it seems that there
are many things that are called jade, this is why you should know a little
about this prized gemstone so you don't get taken. It seems that every
wannabe dealer on web sites such as Ebay call anything green - jade, but
now you know the truth. If it's not either jadeite or nephrite, it's NOT
JADE!!
A
simple steel knife scratch testing can give you a clue about the material.
Use a quality steel pocket knife with short blade so you don't end up slicing
your hand or finger, find a place on the back or bottom of the so called
jade item, and try and scratch a short line in the material. If it's really
jade of either variety , you will not be able to scratch it or raise a
powder. Most jade look a likes are soapstone or some other dyed material
and in general are much softer than either jade, and you will easily be
able to scratch it with a short steel knife point. Soapstone carvings can
be beautiful in there own right, but you should know that is what you
are buying and not be deceived by someone offering a jade statue
or necklace.
Lapis
Lazuli
Beware
of dyed materials that are made to try to look like lapis, for example
dyed howlite. Some lapis is really lapis but has been enhanced by dyed to a deeper blue
to look like a higher grade. Also some lapis has been treated with high
tech dark blue polymers. There is some beautiful royal blue lapis on the
market, but it usually commands a premium price.
Turquoise
Natural
turquoise is often too unstable to be used in jewelry so it is often subjected
to a stabilizing treatment that soaks in various binders such as polymers
to add strength. This is a common trade practice and in my opinion should
not detract one from buying specimens or jewelry containing stabilized
turquoise. Be aware of simulated turquoise ( see Howlite above ), and so-called
re constituted turquoise. Re constituted turquoise is crushed up turquoise
that has a binder applied, then re formed in to blocks which are cut in
to gem stone shapes of carved in to figurines etc. The dealer should tell
you if you are buying re constituted turquoise, it should not cost as much
as natural or natural stabilized items.
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