Colored Gemstone Treatments
Almost all gemstones, including amber, have been treated and enhanced for at least two thousand years and possibly much longer. The Roman, Pliny the Elder (23-79 BC) who famously completed “Natural History” in 78 BC detailed many of the methods used to improve the beauty and wearability of semi-precious and precious colored gemstones.
Pliny writes of heating, oiling, dying, using foil backings and coatings of various sources on all sorts of gems. A few of these methods are still used today in much the same way as they were then. Quite a few more are used with ever greater ease of technology. Undoubtedly, disclosure of the enhancements in the olden days is also still very much the same as it is today-- Gemstone treatments are rarely, if ever, disclosed to the buyer. Caveat emptor!
Today stabilization of certain gems is considered a normal matter of course in the industry. Gems are harvested and mined from the Earth. They are often brittle and sometimes much too soft to be used as they are intended— for jewelry. The next steps involve treatments and enhancements before cutting and creating jewelry. And just what sort of treatment will altogether depend upon the gem itself. Sometimes the human touch is required to render gems into full blown jewels after all-- to fully reveal a gift of nature for human eyes.
We'll use turquoise for our example of stabilization. Turquoise is soft and quite porous in nature. It's an easy estimate to say that today at least 90% or more turquoise is treated or stabilized for use in the commercial jewelry market.
Stabilization is a high pressure process that penetrates what would otherwise be unsaleable chalky material. Without stabilization treatment the turquoise picks up oils and other substances from the body and clothing and over time will turn an entirely different color, mostly dull and gray. The use of plastics such as polystyrene and water glass, also known as sodium silicate “stabilizes” the turquoise and produces a gemstone worthy of wear, a stone which is beautiful and, most importantly, durable. The 10% or so of natural turquoise is generally very thin, beautiful material that is bonded on the back of another material-- not too long ago Native Americans used old phonograph records for this purpose-- giving the turquoise another kind of “stability.”
Stabilization of turquoise is widely accepted in the industry. Iindeed, without it there wouldn't be much of a reason to dig the earth for turquoise, since such a tiny portion of it is instantly beautiful the way we see turquoise today.
Treated Turquoise image caption blank on purpose
Untreated Turquoise image caption blank on purpose
Many, if not most gemstones are not as intriguing in their pristine states as one might imagine or desire. Most are totally unrecognizable. Deliberate falsification is an important and totally different subject, one which we may offer for discussion at another time in Amberology and at our new blog [link to be inserted]. Meanwhile, let's examine another gemstone treatment.
Take the case of blue topaz. I remember as a young girl feeling over the moon with thoughts of owning a London Blue Topaz. There was nothing I wanted more than that dear little rectangle faceted ring in sailing, skyward blue.
Little did I know at the time that London Blue and all other blue topaz is irradiated to produce that stunning blue color—turning it from brown to blue depending on how high the dose. I really did not know that until I did some research. I have since discovered that it is very near impossible to buy a blue topaz stone that has not been irradiated. Now, a little older and wiser, I don't feel so bad at never having acquiring that blue topaz ring.
Now, at a slightly older age, I don't feel so bad at never acquiring that blue topaz ring.
It's just the way it is in the gemstone industry-- most gemstones are treated. Today the customer wants the information that will best help them make their decision when investing money in gemstone jewelry. It really is important for the ordinary jeweler to tell people about their colored stones --”It was probably heat treated.” Because knowledge is power. The more we know, the more we can appreciate the careful, deliberate steps each individual gemstone undergoes on on its journey to delight you with dazzle, color and cut and become a part of your journey.
Heat treatment is applied routinely to amber, rubies, sapphires and tanzanite. It can impact the color. Heat “improves” amber clarity, without it, most amber would be opaque. And the fossil inclusions would remain hidden, unless they were on the edge. Of course raw amber itself usually comes weathered with a thickened outer cortex. In most types of Baltic amber jewelry this rough outer layer is removed and refined away, long before it ever comes to your hand. Learning about the origin of your favorite gemstones also helps us to understand the true cost and the true value of a gemstone. It requires a lump of amber several times larger than the resulting cabochon to create that deliberately handcrafted piece, much amber has been lost in the process. Scales,
or the flat discs seen spinning like stars or galaxies inside your
amber piece are the result of heat under pressure or autoclaves.
Link to Wieslow Gierlowski amber article on our new blog 11-19-2012 publish>>>>>>>>
It is important for us to mention that one major reason we became members of and a “Recommended” company listed with The International Amber Association is to fully participate in a published, industry standard system of such amber gemstone treatment classifications with full disclosure. Equally important, with amber being such an inherently individual gemstone with so much variation- 256 colors!- countless textural and pattern variations!- that without these standardized and long established, we might add, treatments, it would be actually impossible for us to keep our website stocked with 100% one of a kind designs. Instead, we're able to show you a typical piece with a very strong resemblance to the one you will find in your hand within an acceptable, artistic range of variation. We are able to create and deliver consistent jewelry designs to you, as well as a selection of unique designs. Our batches are still very small, quality is maintained and the character and beauty shows through.
If you are deeply interested in the details of amber treatments, we will be publishing some esoteric Baltic amber standards articles at our blog in the next few weeks (the new blog is not going live until later this week as I write on Nov. 18th, 2012 – we'll updat this link when it goes live)
Lovely slab of untreated tanzanite
Tanzanite image photo caption blank>>>>>>>>>>>>>
Nearly all tanzanite is heated at low temperatures to rid the stone of dull, brown undertones and bring out a superior color of cornflower. Occasionally there is lovely piece of rough tanzanite, but it still needs to be heated to 600 or 700 degrees to have the lovely color evenly distributed and practical for jewelry needs. This is just about a universal treatment for most gems – although the heating temperatures and the way they are approached will vary, of course.
Heat treated tanzanite bracelet image blank
Of course, there are many other treatments of gems and gemstone, many of them mentioned over two thousand years ago by the Roman Pliny the Elder which is where we started! The best advice I can give the colored gemstone lovers is the same advice we've been giving year after year. To put it into Pliny's lingo-- Experto crede is a Latin motto meaning, “believe in one who has experience in the matter.”
Your local jeweler and your favorite internet company generally have your best interests at heart and are the source you have come to trust. I know that since 1995 that is the block we have built our company on and imagine that most folks have done business the same way. In today's world, the customer is just so much more informed and the shopkeeper and the customer place such a high value on their relationship, transparency and authenticity make for a genuine relationship-- built on the love of colored gemstones and mutual trust.
--Andzia Chmil Stout, founder Amberjewery.com