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CZ - Luster Quality and Velocity


#1

Many people think CZ is cheap. But the fact is that CZ is the most
realistic diamond simulant ever produced because of it’s beauty!!
It’s beauty not only can compare to diamond, it’s superior to
diamond. CZ can be very beautiful and special and deserve to exist as
jewel in their own right.

WHAT YOU SHOULD KNOW: When talking about luster, CZ is better than
natural diamond for sure.

Don’t believe it? Just look at the facts:

The word “luster” traces its origins back to the Latin word “lux”,
meaning “light”, and generally implies radiance, gloss, or
brilliance.

Dispersion is often known as “fire” or “luster” of a stone, the
higher the better. Why a CZ gives more luster than a natural diamond?
The answer is simple: CZ has a HIGHER dispersion of 0.06 while a
natural diamond got only 0.044. A diamond owes most of its beauty to
its high dispersion. So which is more beautiful when talking about
"luster"?

Now you already know that CZ has higher dispersion than Diamond, but
the more stunning fact is that the ratio of dispersion of natural
diamond to CZ is almost the ratio of resolution of CRT TV to HD TV.
Can’t believe it? Look at the facts:

The resolution of a CRT TV usually refers to 480pixels in vertical
lines. The resolution of a HD TV usually refers to 720 pixels or
higher in vertical lines. The ratio of the vertical resolution of a
CRT TV to HD TV is 1.5 : 1. The ratio shows that the vertical
resolution of HD TV is 1.5 times higher than CRT TV. So, by the same
way of calculation, you will get a ratio of 1.36 : 1 which implies
that CZ owns a dispersion which is 1.36 times more than natural
diamond ! Luster which natural diamond can give is just like the
resolution of an old CRT TV when compare to CZ’s higher velocity of
luster!! Even the highest quality natural diamond is no match to a
well made CZ when talking about Luster.

The Luster Velocity of a single CZ stone is 1.36 times more than
natural diamond. How about more than 100pcs of CZ set on a single
surface?

It’s time to think about Luster Quality and Velocity when you make
your jewelry collection.


#2
When talking about luster, CZ is better than natural diamond for
sure. 

I am going to thank Mr. Chan on behalf of Orchid community for
providing a demonstration that any statement <> can be posted
accompanied with so called “facts”.

Luster is the property which is depended on hardness. The harder
material, the better quality of luster is achievable. Since diamond
is much harder than CZ, CZ cannot possibly achieve luster achievable
on a diamond.

Leonid Surpin
www.studioarete.com


#3

I’m already converted. When I started making jewellery last year, I
avoided CZ’s like the plague, buying white topaz as my choice of
colourless* stone. However, they were so disappointing that I never
actually set any of the topaz stones. I found a supplier of VERY
good quality CZ’s which are extremely well cut and have the clarity
and colour of F/IF, D diamonds and I not only love working with them
and setting them, I also love to wear them because they really are
beautiful. They have so much fire in them that I can’t stop looking
at them!

*A pet hate of mine is when people describe the colour of gems such
as diamond and CZ as “clear”. In chemistry (as in gemology, or so I
understand), the word clear is a point on the clarity scale (common
language, not GIA clarity scale) of stones, ie cloudy (included/
opaque) as opposed to clear (transparent). Top quality Ceylon
sapphires are also clear, whilst still being blue. Peridot are clear
and green, etc. The word colourless is the proper term for such
stones as D,E,F colour diamond, CZ, etc. Again the word “white” is
often used by some suppliers/people, but that best describes
diamonds of G,H colour. Sorry for the rant!

I have rings with SI, G/H diamonds but they’re not a patch on the
CZ’s I buy. I was surprised to find that there is a huge variety in
quality of CZ’s on the market, and there is a lot of rubbish out
there. Much of the stuff found in cheap high street jewellery is of
very poor quality as is much of the loose material. My favourite
jeweller’s supply company sells a set of cheap CZ’s that I will NOT
be buying as they already look cloudy when new!

As I’m working in sterling silver at the moment, I feel that setting
very good quality CZ’s is about right, value-wise. When I move onto
working in gold, I will stump up for diamonds but at the moment I’m
happy with my CZ’s.

Helen
UK


#4

You forgot to mention the hardness of CZ…

What are you selling again?


#5
It's beauty not only can compare to diamond, it's superior to
diamond. 

Sounds like you’re a CZ salesman. Can’t say I agree in any way as it
isn’t only the luster that makes diamond what it is. Nor will it make
CZ better than diamond. I know a number of you on list use CZs and
are happy using them, but they certainly aren’t “superior” to
diamonds (you can start by explaining how the hardness of a CZ is
superior to that of a diamond and go from there).

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#6

Hello Ray,

I’m sure this can will have many worms wriggling to get out! My only
comment is that a dirty CZ looks dull in comparison to a dirty
diamond. Gotta’ keep those simulants absobloominitly clean to sparkle
like a diamond. My rings suffer from soap film, garden dirt, and the
occasional dab of skin lotion. Sure cuts down on the sparkle.

Just my humble observation - and I do like CZs… Judy in Kansas,
where it’s another lovely bit of springtime in August! The turtles
are lovin’ it.


#7

Ray…yeah, all that is true but…is a CZ as durable? Not nearly!

For my money, a diamond is a diamond and a bright CZ is a bright CZ.
Give me a beautiful jasper anyday!!

Cheers from Don in SOFL


#8
Many people think CZ is cheap. 

It is. couple bucks for a fine carat sized gem. Good value for the
money. In part, because it’s cheap…

But the fact is that CZ is the most realistic diamond simulant ever
produced because of it's beauty!! 

It is, indeed, one of the more convincing simulants for diamond.
That doesn’t automatically imply it’s more beautiful. Just close in
visual appearance.

It's beauty not only can compare to diamond, it's superior to
diamond. 

Beauty is in the eye of the beholder, and apparently, you’ve got
some CZ stuck in your eye. Most people I know, while they like and
appreciate CZ, and use it when appropriate in their jewelery, do not
happen to feel it’s more beautiful. It’s a subjective judgment, not a
matter of fact, especially not facts as strangely mangled and tangled
as you’ve managed to present.

CZ can be very beautiful and special and deserve to exist as jewel
in their own right. 

And indeed it already does. As a fine synthetic material. It doesn’t
have the appeal that some feel for rare natural gems, since it isn’t
one. But for a synthetic, it’s well appreciated. You can show this to
be true simply by noting that CZ set jewelry is usually sold
accurately described, not sold masquerading as something else.

WHAT YOU SHOULD KNOW: When talking about luster, CZ is better than
natural diamond for sure. 

False. Luster is a property related to hardness, perfection of
polish, reflectivity, and refractive index. Diamond exceeds CZ in all
these properties, and has a slightly higher luster.

Don't believe it? Just look at the facts: The word "luster" traces
its origins back to the Latin word "lux", meaning "light", and
generally implies radiance, gloss, or brilliance. 

True enough.

Dispersion is often known as "fire" or "luster" of a stone, the
higher the better. Why a CZ gives more luster than a natural
diamond? The answer is simple: CZ has a HIGHER dispersion of 0.06
while a natural diamond got only 0.044. A diamond owes most of its
beauty to its high dispersion. So which is more beautiful when
talking about "luster"? 

No. Fire or dispersion is NOT luster. It’s the degree to which a
material refracts red light a different amount than blue light, (and
the rest of the spectrum, which results in white light being broken
apart into seperated colors as it’s refracted around and through a
gem. CZ is indee higher if dispersion, and this results in more of
the light reflected to the eye of the viewer being in the form of
colored flashes of light rather than white light. All these rainbow
flashes of light are indeed pretty, but when there too much, can
actually look a bit garish. Again, it’s a matter of taste. More is
not necessarily and automatically better, unless you happen to like
it. Many people, comparing diamond to CZ, prefer the somewhat more
subtle fire of a diamond to the sometimes garish colors of CZ. Others
will like all that color in the CZ and prefer it. Again, it’s a
subjective choice, not a mathematical or factual certainty to
determine which is more beautiful.

Now you already know that CZ has higher dispersion than Diamond,
but the more stunning fact is that the ratio of dispersion of
natural diamond to CZ is almost the ratio of resolution of CRT TV
to HD TV. Can't believe it? Look at the facts: The resolution of a
CRT TV usually refers to 480pixels in vertical lines. The
resolution of a HD TV usually refers to 720 pixels or higher in
vertical lines. The ratio of the vertical resolution of a CRT TV to
HD TV is 1.5 : 1. The ratio shows that the vertical resolution of
HD TV is 1.5 times higher than CRT TV. So, by the same way of
calculation, you will get a ratio of 1.36 : 1 which implies that CZ
owns a dispersion which is 1.36 times more than natural diamond !
Luster which natural diamond can give is just like the resolution
of an old CRT TV when compare to CZ's higher velocity of luster!!
Even the highest quality natural diamond is no match to a well made
CZ when talking about Luster. 

Ok, now you’re delving into the realm of the twilight zone. The
performance of televisions has nothing to do with, and isn’t related
in any meaningful way, to the optics of CZ versus diamond. Your
statement is about the same as claiming with much enthousiasm that
because the paint on your car has more blue pigment than the skin of
a nice ripe red apple, it thus would stand to reason that the fish
you buy next time you go grocery shopping will end up tasting more
like mutton. It’s utter nonsense, of course, and so is your mangled
set of numbers there.

The Luster Velocity of a single CZ stone is 1.36 times more than
natural diamond. How about more than 100pcs of CZ set on a single
surface? 

Luster velocity? There’s a new one. Congratulations. Not only have
you managed to mangle gemstone optics to a heretofor unprecedented
degree, but now you’re inventing your very own gemological properties
and terms. Nobody else in the world who knows anything about gemology
has ever heard the term “Luster velocity” so perhaps you’d better
define it for us. Perhaps it’s the speed with which an otherwise nice
gem like CZ looses it’s appeal and luster when promoted by someone
who doesn’t know what he or she is talking about?

or perhaps your whole article started out as a reasonably accurate
document written in, for example, Chinese. and you’ve generated your
Orchid post by feeding it to an online translation engine? Could
that be it? Some of the results one can get that way are lots of fun.
Recently I heard of a Chinese restaurant owner who, wishing some of
the tourist dollars during the Olympics, decided to put an english
language sign on his restaurant giving the name, etc. So he entered
his retaurant name into an internet translation site, and carefully
copied the returned result to his sign. His restaurant is now clearly
labeled for all the world, “Translate server error”. I don’t know, of
course, if this is true. Just a story from the net. But I’m guessing
your article about CZ started in some other form, and this posting
might be called “gemology translate server error”… Because frankly,
Ray, you need to either proofread better, or go take some gemology
classes. You’ve got a lot wrong here. Too bad, because CZ is a useful
and pretty gem material. It deserves better than this.

Peter Rowe


#9
I know a number of you on list use CZs and are happy using them,
but they certainly aren't "superior" to diamonds 

You’re obviously absolutely correct Daniel. I am happy to set CZ’s
in sterling silver at the moment, because I get the “look” of great
diamonds for a budget that I feel fits with sterling silver.
However, if I was asked whether I would prefer D/IF diamonds or D/IF
CZ’s regardless of budget, it would obviously have to be diamonds,
hands down. When I change to working more in gold, I will compromise
and probably go for G/H colour and SI clarity diamonds rather than
CZ’s but for now I’m happy with them.

Helen
UK
http://www.hillsgems.co.uk


#10

Hi Folks…

I, too like CZ for what it is… A good looking synthetic, that’s a
good diamond simulant…

I think that one could reduce what some folks think is its garish
fire apparently by tweaking the cut…

I once saw a post on Ebay’s J, G & W forum about it turning
cloudy… Poster was a moissanite vendor…

So…I took a 6.5 mm white CZ (Rio Signity) and placed it on the
sill of one of my Eastern windows…

It’s going on its third year…no cloudiness…

Where its downfall as a gem material is, IMO, is
durability…leaving rarity out as a criterion…

I know it’s hard…8.5 Moh’s, but the stuff seems to chip
easily…

Just my observations…

Gary W. Bourbonais
L’Hermite Aromatique
A.J.P. (GIA)


#11

Ok, I’ll confess if no one tells anybody from gemology online. I love
CZ. Not the clear stuff really, but the coloured stuff. I got lots of
different raw material, and when I think no-one is looking, I’ll cut
a new stone in a new shape and put is in my faceted CZ box. I got
colour change, black, blue, orange, and many other colours. All so
pretty and useless. For high end jewellery. But, boy, so pretty. I

http://www.meevis.com
http://hansmeevis.blogspot.com


#12

Dispersion and luster are two different things. I believe you are
using the term “luster” incorrectly. And trust me, diamonds have a
lot more going for them than just dispersion. If beauty to you is all
about dispersion, maybe you should be singing the praises of
strontium titinate or some synthetic rutile rather than CZ!

www.carrienunes.com


#13

Hi Helen,

I’ve been cutting CZ for over thirty years.

Today, most CZ that makes it to the cutting stage is of the same
quality,about E/F color and perfectly clean, although some is
available with inclusions.

The reason that much of it in the marketplace looks cloudy is
because it is poorly polished, which the microscope will reveal.
Standard polishing overseas is done in one of two ways, either with
grit or with chemicals.

The chemical method (hydrofluoric acid!!) results in very rounded
facet edges, creating a cloudy look sometimes.

Overseas cutters use what amounts to an 18,000 grit diamond. This is
deemed an “acceptable” polish commercially.

The precision cutters in China who produce H&A pattern CZ, use
50,000 grit, which is a pretty nice polish. If the stone has proper
meets and angles, it will be quite difficult to differentiate by eye
from diamond by most people. It’s a fr cry from what you see in most
"costume" goods out there.

I’ve been asked over the years to cut all sorts of CZ as a diamond
simulant or as a finished product on its own, especially in the
color-changing varieties. I use either a 100,000 or 200,000 grit
finish, which takes MUCH longer to accomplish, but the results can
be spectacular.

I’ll add a couple thoughts:

CZ is far too brittle to expect it to hold up in a ring for very
long. It’s just not that tough. hard, yes, tough, no.

The dispersion of CZ is half again as high as diamond, a sure
give-away. While it may be pretty, it doesn’t look like diamond to
me. Colorless YAG makes a better diamond simulant, IMO, and is much,
much tougher and heat resistant than CZ. I market colorless YAG just
for this purpose, because it is so durable.

It’s a lot more expensive than commercially cut CZ, because I do
charge for custom cutting and I’m not cheap.

Wayne


#14

You’re right, Gary.

All MY scratch tests show CZ to be closer to 8 in hardness (Mohs
scale), but it is rather brittle, which is why it does not hold up
well in a ring. Hardness and toughness are not necessarily related.

Jadeite is only around 6. or 6.5 in hardness but is one of the very
toughest minerals. It’s nearly impossible to chip.

Wayne Emery
www.thelittlecameras.com


#15
Dispersion is often known as "fire" or "luster" of a stone, the
higher the better. 

As evidenced by the continuing popularity of Fabulite and YAG? :stuck_out_tongue_winking_eye:


#16
I once saw a post on Ebay's J, G & W forum about it turning
cloudy.... Poster was a moissanite vendor... 

I thought the cloudiness was due to the facet edges being abraded?

I know it's hard....8.5 Moh's, but the stuff seems to chip
easily.... 

A bit like diamond being hard as in can’t be scratched by anything
but another diamond (Moh’s 10), but not necessarily tough (chips and
breaks if hit).

Helen
UK


#17
I'll cut a new stone in a new shape and put is in my faceted CZ
box. I got colour change, black, blue, orange, and many other
colours. All so pretty and useless. 

Keep cutting and collecting. Maybe one day when the earth’s natural
resources are running lower, CZ’s will be more valuable and not have
such bad press. People will pay you good money for them then!

Helen
UK


#18

Hi Wayne,

Thanks for your email. I have been amazed at the difference in
quality you can get with CZ’s. I have two VERY good suppliers of
very well cut CZ and will not buy from anyone else. I know I keep
harping on about my CZ’s, but they are top quality with extremely
well meeting facets - all facet junctions meeting where they’re
supposed to (kite to kite and kite to table facets all meeting with
sharp points not lines, etc). Every stone I buy gets thoroughly
louped to check for such things. I’ve never tried YAG so can’t
compare them to my CZ’s. I’d be interested to see an example.

You’ve been working with diamonds, CZ’s and YAG’s for many years so
you can probably tell at a glance which is which, but for a relative
beginner, I’ve always had a good eye for cut, inclusions and chips/
scratches in gems even with the naked eye, and even before I was
buying loose gems. I’m very fussy when it comes to step cut gems for
example. Facet edges that are not parallel on an octagon cut gem
jump out at me immediately but I see people selling jewellery with
very poorly cut stones all the time. My fussiness with regard to
detail is what is making me improve, as I’m super critical with the
finish of what I make as well as when buying gems.

As for heating them, I’ve successfully heated many of my CZ’s and
never had a problem. They all had their facet edges intact
afterwards. As a recent experiment when making a pendant, I tube set
some CZ’s and then soldered them onto a backing plate with holes
drilled in it. All stones in their settings stood up to repeated
soldering steps. And I remembered not to quench, yay!!!

However, that being said, I am looking forward to working in gold
and using diamonds too.

Helen
UK


#19

CZ is notoriously difficult to polish. 50,000 or 100,000 grit
diamond is the preferred medium and even then it can be tricky. I
suspect that’s why so much of the commercially cut CZ is cloudy.

RC


#20
So...I took a 6.5 mm white CZ (Rio Signity) and placed it on the
sill of one of my Eastern windows.... It's going on its third
year.....no cloudiness... 

CZ is a cubic form of zirconia oxide. It does not exist in nature
(there are reports that small crystals were found recently ) because
it is unstable. In manufacturing process CZ is stabilized with
additives. Every manufacturer have it’s own recipe and even than there
are different qualities can come out from the same batch. Some of the
earlier versions could start to break down and it would manifest as
cloudiness. I believe that this problem was solved long time ago.

Leonid Surpin
www.studioarete.com