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Science project

stephsaa

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My son would like to do his science project on how to tell natural diamond from cz.
I have diamond tester, loop, RI equipment, however I am looking for more "street person" ways.
Need help :)
 

mercoledi

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I've heard two, but they might be completely bogus (but fun to try!). One is the if a CZ and diamond are both placed table-down on a printed surface, you can read the printing though the CZ, but not the diamond. The second is that if breathe on both to fog them, the diamond will clear more rapidly than the CZ.

Like I said, I'm not sure they work, but if you have a diamond and a CZ lying around, why not try?

In my experience, CZs also have a different spectral flash; it's hard to describe, but to my eye they produce colors in a way that diamonds don't, and so can sometimes be eyeballed that way as well.

ETA: A google search produced a similar list, including the three I mentioned above: http://www.wikihow.com/Tell-if-a-Diamond-is-Real
 

daintyG

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Not sure if this is what you're looking for, but a diamond certified by GIA will have an inscription you can see with a loupe. Sounds like a fun project!
 

Niel

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Not sure how but ive heard they look different when in water. Maybe google that see what turns up
 

yssie

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Also Moh's - diamond > cz

daintyG|1357838442|3352223 said:
Not sure if this is what you're looking for, but a diamond certified by GIA will have an inscription you can see with a loupe.
Not necessarily - may not have an inscription, may need higher magnification to see it (smaller stone w/ thinner girdle)
 

Jim Summa

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If the stones are loose you can tell by the heft, CZ's are quite a bit heavier. If you have a carat diamond kicking around you can try it out agaisnst a 6.5mm CZ. Sort of a street thing.

The polish (under reflected light) just isn't quite right. You can pick it up at the facet junctions, they look rounded. Guy told me once if you polish a set or mounted CZ on your shirt sleeve the facets will get rounded...diamond will never do that...I hear.
 

JulieN

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Breathe on it and compare how long it takes the fog to evaporate.

Explain why.
 

denverappraiser

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Table down, shine a light through the back over a piece of paper a centimeter or so away so the stone acts as a lens. The pattern you see on the paper is quite different.

Grind the subject stone into a fine powder. Burn the powder and examine the flame through your handy UV Spectroscope. Listen carefully to the volume of the screaming from the owner while you do this. High volume means diamond.

Here's a cool test if it's big enough. Hold the stone in between your thumb and first finger and touch it to an ice cube. A diamond will burn through it like a soldering iron. A CZ won't. It's a little hard to do this with stones below about a carat but with a 3 or 4 carater it's a really fun effect.
 

denverappraiser

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It takes a bit of practice so I'm not sure a school project is the place to show it but CZ girdles usually look very different under magnification. Diamonds have very sharp facet junctions, naturals, extra facets, brunted or faceted girdles.

Inclusions are a giveaway. CZ's can have feathers (rarely) but you'll never see a mineral inclusion in one.

If it's not 'new', CZ's wear very differently if you look at the facet junctions around the edge of the table. CZ's are usually flawless, diamonds usually aren't.

CZ's are almost always very very white. D+. If you see color it's a strong clue for diamond.
 

kenny

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Not exactly science, but true in 99.999999999999% of cases.

Diamond is very expensive.
CZ is very cheap.
 

Karl_K

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hold it so your finger is under the table, look through a pavilion facet with a loupe, see your fingerprint clearly its cz.
 

gregchang35

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Just another question for this science project... all the above seems to test the diamond/cz when it is a not set ie loose.

what if the diamond or CZ is already set in a ring or earring; how can you distinguish the difference?
 

Karl_K

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gregchang35|1357860398|3352563 said:
Just another question for this science project... all the above seems to test the diamond/cz when it is a not set ie loose.

what if the diamond or CZ is already set in a ring or earring; how can you distinguish the difference?
Experience.
Looking at facet junctions but precision cut cz is harder than the common ones.
The look of the crystal surface is different.
Diamond tester will work except for the dlc coated ones.
 

diamondseeker2006

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denverappraiser|1357855805|3352499 said:
Table down, shine a light through the back over a piece of paper a centimeter or so away so the stone acts as a lens. The pattern you see on the paper is quite different.

Grind the subject stone into a fine powder. Burn the powder and examine the flame through your handy UV Spectroscope. Listen carefully to the volume of the screaming from the owner while you do this. High volume means diamond.

Here's a cool test if it's big enough. Hold the stone in between your thumb and first finger and touch it to an ice cube. A diamond will burn through it like a soldering iron. A CZ won't. It's a little hard to do this with stones below about a carat but with a 3 or 4 carater it's a really fun effect.

:lol: Love #2.

I really want to try #3. So please send me a spare 3 ct stone.
 

heliotrope

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FYI - #3 works a treat - the geek in me just had to test this one out with my 0.5ct tranny :tongue:

(even retested with a CZ and a tourmaline to watch the difference)

but if anyone wants me to retest with a 3ct - please feel free to send one my way!!
 
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i am not so sure about the table down method as i think the cutting style of the stone will affect what you see.

For example, if you put an emerald cut REAL diamond face down versus putting a real round brilliant cut face down, you will get different appearance but that doesn't mean the emerald cut diamond is a fake stone.
 

Christina...

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I think the breath test is a great one, however if the natural diamond is dirty/oily it can take as long for the fog to dissipate as it does for the CZ. Make sure both stones are clean before trying this one.
 

yssie

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denverappraiser|1357855805|3352499 said:
Grind the subject stone into a fine powder. Burn the powder and examine the flame through your handy UV Spectroscope. Listen carefully to the volume of the screaming from the owner while you do this. High volume means diamond.

Is this speaking from experience? :bigsmile:
 

stephsaa

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Thank you all so much for your help. We are going to have a fun weekend. Got a vendor in town to lend me a few large stones and got a few cz's from stullers. I will let you all know how the grade turns out. Teacher emailed me today asking if it was my son or me doing the project. lol... usually the parents endi up doing science class all over again in parenthood!
 

Christina...

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stephsaa|1357883065|3352786 said:
Thank you all so much for your help. We are going to have a fun weekend. Got a vendor in town to lend me a few large stones and got a few cz's from stullers. I will let you all know how the grade turns out. Teacher emailed me today asking if it was my son or me doing the project. lol... usually the parents endi up doing science class all over again in parenthood!


lol This is so true! Funny how it's much more interesting the second time around though. :lol:
 

justginger

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This sounds like a very cool project - and awesome for a vendor to lend you the necessary (expensive!) bits and pieces.
 
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