Thursday, May 16, 2013

I got a rock... (part 1)


For those of you who are younger than i am (that would be most of you) the headline is from a Charlie Brown (tm) Halloween special, where everyone else gets candy and Charlie Brown looks in his bag and says: "i got a rock.." Poor Charlie Brown.

For many of us, though, we would be delighted to get a rock. rocks are wonderful!  Rocks of some kind are important in jewelry.  Yes there are technical differences between rocks, and stones, but lets cut to the important stuff:

what the heck is it?  (part 1) and how do i take care of it? (part 2)

the two questions are related. some stones used in jewelry are very delicate, some are "hard as rocks" and if you do not know what it is you have, you have to assume its delicate.

The questions that tell you "what the heck is it?" are:

What kind of rock is it?
What was done to your rock?

What kind of Rock is it?

You would think this would be an easy question to answer, wouldn't you?  If it says a single word , like "Amethyst" or "Topaz" then it generally is exactly that (but not always).  The problem comes up when the name is descriptivce and has places or other words attached to it.
"Picture Jasper"
"London Blue Topaz"
"Korean Jade"
"Mystic Topaz"

so what are they?  Are they Jasper, Topaz, and Jade? or something else entirely?  Whenever you see a compound word used to describe a stone, you need to do a bit of research to figure it out.

Picture Jasper is a type of Jasper (ok, its Jasper) that has natural markings (ok, its not created) that make "pictures" or look like images or landscapes. (ok.. this is a straight forward desciption of what THIS kind of Jasper happens to look like)

London Blue Topaz is a Topaz (ok, it is a topaz) that has been irradiated (we will cover that later) to create a specific shade of deep blue (color ). This name is a "trade name" (oh, its a marketing name, and probably trade marked).

Korean Jade is a type of Serpentine (woah! its not Jade) with a specific coloring, found in many places worldwide... (not Jade, but Serpentine, and should be cared for as "Serpentine")

Mystic Topaz is really Topaz, (the stone is Topaz) but has a treatment (see next section) that is very delicate.

Get the idea?  A compound name may simply be descriptive, or tell you why this type of Jasper (for instance) is different that the other kind, but it could mean that it needs different care or that it is, in fact, NOT the stone you think it is!

Obviously if you want to take care of your jewelry properly you need to know what kind of rock it is first!

Some types of stone are very sensitive to light, some to heat, some to chemicals (like swimming pools and cleaning products) and a few , a VERY few, can go from a lying out in the sun at a swimming pool to cleaning the floors and come out just dandy.

Knowing what your stone actually IS is important to caring for it (and cleaning it) properly!

What was done to your rock?

 Now it gets complicated.  Gemstones, and other pretty rocks, are subjected to all sorts of treatments to make them "prettier" to get rid of flaws, or to let them survive encounters with things like chlorinated water.
What treatments are "acceptable" and which ones are fraud, can be a very tough argument.

Heat Treatment: this is one of the oldest ways of improving or altering a stone.  We have documentation of this being done back to the earliest written records, and we have evidence of it from before written history.  There is nothing wrong with this, although of course it should be disclosed to the buyer.
Almost all Citrine, Carnelian, and Amber on the market today has been heat treated. This is usually permanent, and stable.

Dyeing: is a treatment that is considered usual and normal in some stones, and i dislike intensely. 
Real stones can be dyed to enhance their color or to make them look totally different.  Often this means "make them look like a more valuable stone". Turquoise, as an example, is often imitated by dyeing  various stones that are worth far less money, but real (if poor grade) Turquoise is often dyed to give it a better color!  Dyed stones can lose their color if exposed to the wrong chemicals or cleaners.

For myself, personally, i only use dyed stones that CANNOT be mistaken for something else.

dyed Magnesite
The above picture is dyed Magnesite.  This stone (and it is a real stone) is naturally sort of putty colored, with inclusions in a kind of crackle pattern.  It is often used to make imitation (fake) Turquoise or Lapis, because the pattern on the stone (which doesn't take dye) mimics the look of a real Turquoise.  I will not buy it in colors that mimic natural stone, because i don't want anyone mistaking it for something it is not.  It makes a very pretty piece of jewelry, though...
Magnesite, dyed blue, wrapped in three metals

Irradiation, something that can happen naturally deep in the earth, is often artificially used to create or change a color in a stone. Topaz is the best example of that.  ALL blue Topaz is irradiated.  A very very few pieces were naturally created by radiation in the earth, but unless you curate a museum, or dig your own, assume all blue topazes are real Topaz that has had their color altered.  This treatment is permanent and the colors *usually* do not fade.
London Blue Topaz. The color is created by radiation

Filling, Oiling, and Stabilizing:  Here is where it gets increasingly complicated.  Each of these types of treatment can be good, or bad.  It can mean something very simple, or a complete change in the stone.

To start with the simplest one, Stabilizing, this means a resin has been forced into the stone at high pressure.  it changes the characteristics of the stone, a lot.  On the plus side it can take a fragile stone like Turquoise, and make it more resistant to chlorine, and other hazards, but it can also be used to take "waste" Turquoise and pass it off as good Turquoise. A lot of whether this is acceptable or not depends on if it is properly labeled, and whether any color was added.

Emeralds (and every member of the Beryl Family) naturally have very small cracks in the stone.  In Emeralds these cracks are filled by "oiling" which makes these natural cracks less visible. This is an accepted and usual practice...UNLESS they also use color (dye) to change the apparent color of the stone... and you wont be able to tell. This is one reason why buying a GOOD Emerald is a tricky purchase

Assembled or Reconstituted:  This means that bits of a real stone have been fused in some fashion, often with resin.  This is sort of like a fish stick, or a chicken nugget, compared to a real fish fillet or chicken breast..  I wouldn't mind this, except that all to often the stones end up being sold, and re sold, and gifted, and somewhere along the way the fact that this is NOT the real deal gets lost.  This is most commonly seen in Opals, Amber and Turquoise.

Coated:  Applying a coating to the surface of a stone can make some incredible effects.  It is, however, able to fade, or be scratched off, and is usually sensitive to chemicals. "Mystic Topaz" is coated... and really quite lovely, but too delicate for me.

a very well cut and treated Mystic Topaz, from Gemselect

Obviously you also need to be aware of outright fakes.  If you think something is a pearl, and its actually glass, plastic, or resin, then that is a fake not a "treatment".  That more or less falls under "what kind of rock is it".

Knowing what kinds of fakes are commonly available for different stones will help you identify potential problems.

Links and Sources:

Jade earrings and the trade routes

My Etsy shop

Gemstones, By Cally Hall (book): an easy to read book, with color pictures, that is fairly accurate.

Gemstones of the World: by Walter Schumann (book): intended for someone with more background in geology or gemology, it is one of the best for identifying possible fakes, and which stones can be confused.

"I got a rock... (part 2)" blog post.

Thursday, May 2, 2013

Precious Metals, an introduction

Precious Metals?

A lot of people get confused about the term "precious metals" when it is used in jewelry.   It simply means metal that has a significant monetary value in and of itself, not just for "art".  Most Precious Metals were used AS money at some point, and in many cases used to back the value of money when printing made paper money possible.

This doesn't mean  that good jewelry cannot be made from less valuable metals, of course!  I have made a lot of very nice pieces in copper, and lesser metals are often combined with precious metals for artistic reasons.  However it pays to know a bit about the labeling, and uses, of previous metals.

The better known precious metals are gold, and silver.


Is it real?  Sometimes you see labels on things that say "gold" but they are not real gold.  Usually these items are just gold colored.  Every now and then you will see something labeled gold, with some kind of additional word, like "jewelers gold" or "filled" or "plated".  This can be very different things....

Real Gold is labeled  in "karats", with 24 k  gold being pure gold (and too soft to use in most applications).
Different countries have different laws about gold, and different expectations.

In the USA most jewelry is 14k gold, or just over half gold and just under half other metals.  These other metals are used to give the gold more hardness and scratch resistance. 

Depending on what "other metals" are used you can get different colors of gold.  For example: White Gold is admixed with a white metal... often nickel.  the problem is that many people are allergic to nickel and can react very badly to it.  White Gold can also be made by admixing other metals, like palladium, but its a bit more expensive. If you are nickel sensitive, always ask what metal was used in your white gold!

Because gold is expensive, people often use gold plate.  Gold plate means a THIN layer of gold on top of a less expensive metal (usually brass).  Gold plate can chip, or peel, if not cleaned carefully, or if it gets scratched, and the metal underneath can often cause irritation. People who are sensitive to "base metals" like nickel, should probably avoid gold plate.

Gold-filled, however, is very different.  Instead of a thin coating of gold, like gold plate, a gold filled item is a thick hollow tube of gold, that was filled with another metal (often brass, yes).   It is hundreds of times thicker than gold plate and not very prone to scratching or peeling.  It can be very difficult to tell a "14k Gold-filled" item from a solid 14k Gold item.

(For a Gold Filled Item the abbreviation "GF" must be added, so an item stamped "14k gf" is gold filled)

Vermeil is a special case.  Vermeil is a gold plate (a thin layer of gold) on top of  Sterling Silver!  This is the exception to the rule about not wearing gold plate if you have  metal sensitivities.  As long as you are not sensitive to Sterling Silver, of course!


With Silver you are usually only dealing with a couple of basic questions:
Is it really silver? or just silver colored?
Is it Sterling Silver, or Fine Silver?

Anytime you see a place name be very wary. Its not always fake, sometimes its a marketing question, but "German Silver" is another name for nickel, and "Hill Tribes Silver" means it was made in a specific place, out of real silver!  So if you see a place name on your "silver" always ask what it means!

Sterling Silver is not pure silver;  A lot of people get confused by that.  Sterling silver is .972 silver, and .028 something else (that's not a lot).  Usually the silver in this mixture is mixed (alloyed) with copper.  Now i love Sterling Silver, but as a jeweler the copper sometimes causes some issues, like making it a bit trickier to solder.  Sometimes you get some metals mixed into silver, sold as "Sterling" that shouldn't be there, like nickel.  This is why i always sourced my sterling silver very carefully, to make sure it was what it should be!

Sterling silver is also often plated with another metal to stop tarnishing!  this is different than "silver plate" (see gold plate, above) its real sterling silver plated with a silver colored metal that doesn't tarnish...
now that silver prices are climbing, we have "silver-filled" on the market!

No one used to make silver filled wire or jewelry, it just wasnt worth the time, but now that silver prices are so high we are seeing silver filed on the market.  Silver filled should also be labeled (like "sterling silver filled") but as with gold, when you buy something second hand, you never know.

Fine silver, my favorite, is .999 pure silver.  Because it has no copper admixed it doesn't tarnish as much, and it behaves better when you heat it to make head pins.  Some people who react to Sterling Silver can wear fine silver, so its worth giving it a try.

There are other precious metals of course.
Platinum is the one most people know.  Its very hard to work, so most small jewelers don't handle it, but its fairly non-allergenic and sturdy.

Aluminum used to be a precious metal, did you know that?  It was worth more than silver until a new technique made it possible to extract the ore easily.  That dropped its price so much that now its used instead of "tin" foil!

There are many other metals used in jewelry work: Niobium, copper, brass, bronze, pewter, and more.  There is nothing wrong with using a less valuable metal in jewelry!  (or no metal at all) I have several of my favorite pieces that were primarily made in copper and brass.

I just make sure the ear wires (the part that goes through my ears) is silver or gold, or stainless steel. After all, that's the only part of an earring that actually has to touch my ears!