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Trivia - Zircon is not cubic zirconia


#1

Ok, after an unfortunate incident with my mother and a local jeweler
the other day I have to ask everyone here…

You DO know that Cubic Zirconia is NOT the same thing as a Zircon
right???

Craig
www.creativecutgems.com


#2

Hello Craig

Couple of useful readings:

Zircon Group - A Nesosilicate, By Edna B. Anthony

Gem Dealers’s Secrets - Handbook for the Gem Buyer - Zircon

hth
mark in prague


#3
Ok, after an unfortunate incident with my mother and a local
jeweler the other day I have to ask everyone here.. You DO know that
Cubic Zirconia is NOT the same thing as a Zircon right??? 

Depends on who you’re talking to…… People make assumptions
when the see the term Zirconia in anything…

Zircon is a natural (Ma Nature made) stone, which in most forms is
double refracting… Zircon is soft kinda…Moh’s 6.5-7.5… Zircon
got a bad rap when it was done as a diamond simulant…it has a
decent RI, the fire is kinda close to diamond…but it got tainted
as a cheap simulant… Especially after a bit of wear…

It is a great looking natural stone in it’s own right…but it has
to be protected…

Chemically…ZrSiO4…is a silicate…

CZ is man-made…although to call it a synthetic is maybe a
misnomer… CZ has been found in nature (read that somewheres, but
escapes me at the moment) , but nothing of any kind of a gem
quality… So maybe should be called a man-made diamond
simulant…lower RI than diamond, but higher than Zircon… CZ
hardness can be as high as 8.5… More fire than diamond…and
zircon… CZ is single refracting… CZ is heavier than either diamond
or zircon… So…one looks at CZ by size, rather than carat
weight, to deal with it coherently…

Chemically…ZrO2…an oxide… Though I’ve seen something
somewheres about Yttrium added into it…?

Zircon chips easier than diamond or CZ… CZ chips easier than
diamond…

Once upon a time, a Moissie dealer on Ebay was rambling on how CZ
gets “cloudy” due to exposure to light, etc…

So…I took a 6mm RBC white CZ, and also a deep purple 8mm RBC CZ
and set them in an east facing window in small pharmacy type style
caps, and stashed away their bretheren for controls… This is
commercial basic stuff, not even the nicer CZ like Signity or
anything…

That was 3 years ago…

No cloudy anything, nor fade in the purple…

I have managed to chip (10X) some of the facet lines of the 6mm
white, due to my klutzy handling of it when checking it against my
controls over the years…

I’ll run it for a few years more… I realize the window glass
cuts out a lot of the UV of sunlight… But I’m thinking the Moissie
dealer did not really know of what she was speaking…

BTW…this isn’t all by memory, I cheated with Schumann and Simon
and Schuster… for the spec numbers…

I like CZ…it’s fun to fool around with… And colors with the
fire…

If only it wouldn’t chip…

SIGH

Gary W. Bourbonais
A.J.P. (GIA)


#4

Cubic Zirconia is the same as Zircon, just different names same
stuff.

Thor


#5
You DO know that Cubic Zirconia is NOT the same thing as a Zircon
right??? 

Yeah, one is man made never appearing in nature and the other is
mildly radioactive perhaps best avoided for wear in airports. But I
can see where the name game might cause confusion.

Norah Kerr
www.besmithian.com


#6

Hi Craig

I have often had to explain this to my clients.

Zircon is ZrSiO4, Zirconium Silicate

“Zircons reputation has suffered of late due to the introduction of
a diamond simulant. So for the record, zircon is NOT the same
material as the artificial gem material Cubic Zirconia (or CZ).
However with that in mind, zircon has been used as a diamond simulant
both for innocent and nefarious reasons. Zircon resembles diamond in
luster and fire and colorless zircons have been mistaken for diamonds
by experienced jewelers. Zircon can make a very attractive and
affordable gemstone. It is found in browns and greens but can be heat
treated to beautiful blue and golden colors. Colorless material is
produced in this way as well. Zircon is the December Birthstone.” For
more info (the rest of this quote) go to

http://mineral.galleries.com/minerals/silicate/zircon/zircon.htm

“Cubic zirconia (or CZ) is zirconium oxide (ZrO2), a mineral that is
extremely rare in nature but is widely synthesized for use as a
diamond simulant.” For the rest of the info go to

Karen Bahr
Karen’s Artworx


#7

Hi Craig,

I just was just looking up spinels in my gemstone book, and came
across this info:

Since 1910 synthetic spinel has been produced to imitate diamonds,
aqua-marine, sapphire and ZIRKON.

Spinel happens to be mohs scale 8, and interestingly has the same
crystal structure as diamond. (CUBIC).

I would imagine that a synthetic spinel would also be mohs 8 and
Cubic structured, so… a synthetic spinel with a structure that is
CUBIC imitating a ZIRKON would therefore be named CUBIC ZIRKONIA??!!
REAL ZIRKON is in my book mohs 7.5 and has a crystal structure that
is TETRAGONAL whatever that is!

So i kind of like the synthetic spinel as being our CZ. No idea if
this is the correct answer but sounds good to me.

Chris Mead
cmsettingsATyahoo.co.uk


#8
I just was just looking up spinels in my gemstone book, and came
across this info: <snip> 

Spinel is singly refractive, zircon is double refractive. Spinel has
a much lower RI than CZ and has a lower dispersion as well.

Craig
www.creativecutgems.com


#9
So i kind of like the synthetic spinel as being our CZ. No idea if
this is the correct answer but sounds good to me. 

Cute and fun, but not right, I don’t think Spinel has any Zirconium
in it which is the element that gives the name to the other two and
thus causes all the confusion.

Also I think that even in synthetic form Spinel doesn’t have the
colour range that CZ does. I wanted to sound more intellegent and
look up the chemical coupmounds and was tempted to spout off about
idiochromatics vs allochomatics… but I can’t find my refferance
book and so all I’ve got is what is in my pointed little head.

Besides there has been no natural (gem quality certainly) CZ, where
as history has a few natural spinels, usually mistaken for ruby, The
Black Prince’s Ruby comes to mind.

I get the impression that Zircon was a lot more popular a few
decades ago.

Norah Kerr
www.besmithian.com
who college certificate for gemmology got lost in the mail


#10

http://webmineral.com/data/Zircon.shtml

Craig
www.creativecutgems.com