Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
The above picture contains 12 colorless, round faceted gems, with 12 unique identities.
It is my task ( because I have chosen to accept it) to positively identify all these gems.
Let's see what we can find out.
The first thing I'm going to do is weigh all the gems and measure them. If I get confused, or the gems get mixed up, I can put them back in order again. The most useful measurements are the weight and the depth (although I have also taken diameter measurements).
A. 1.763 ct.; 3.93mm depth
B. 0.091 ct.; 1.71mm depth
C. 0.319 ct.; 2.63mm depth
D. 1.476 ct.; 5.05mm depth
E. 0.820 ct.; 3.61mm depth
F. 0.254 ct.; 2.54mm depth
G. 0.233 ct.; 2.74mm depth
H. 0.623 ct.; 2.56mm depth
I. 0.316 ct.; 2.87mm depth
J. 0.329 ct.; 2.29mm depth
K. 0.313 ct.; 2.32mm depth
L. 0.647 ct.; 3.25mm depth
Secondly, I'll test them with the Thermal Diamond Tester:
B and E register to be diamond, all others not.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
We know that if a stone reacts as "diamond" to a thermal tester it can be diamond or moissanite.
I found a zircon inclusion with a radiation halo, extra facets and no doubling of the facets in gem E so that is the diamond.
Since all 12 gems are different, that means B, by elimination, must be moissanite. Looking at it thru the table, there was no apparent doubling of the back facets, BUT when viewing the back facets and culet thru the upper bezel facets, doubling was obvious.
So so far:
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Yeah.
I'm going to collect information and than move this over to the quiz section later in the day. The stone I am working on now is giving me grief.
I'm going to take a break.
Could you list all the stones they could be, all the colorless ones? Or is that just vast? Would clear/white sapphire be an option? I guess one has to be a CZ.
Are they alll untreated, unheated, non-synthetic?
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Shoot...this one fell through the cracks. I identified these stones and them sent them back to the owner, without finishing the thread.
As I recall the set had
diamond
moissanite
quartz
colorless sapphire
YAG
GGG
strontium titanate
cubic zirconia
colorless topaz
colorless synthetic spinel
zircon
synthetic rutile
But I can't remember which one was which one at this point.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
I used a combination of thermal tester, polariscope/consicope reaction, RI, dicroscope, SG, UV, Spectroscope and Microscope.
People often point out that my system is too labor intensive, but I have a large table set up with instruments in order and the time it takes to walk around the table, I can get all the specs.
dev's been collecting all different types of clear stones to harrass me with when I do my gem id course...he's such a sweetie
_________________ Beth http://www.prettyrock.com http://www.prettyrock.com/2012facetingcompetition.htm Avon Breast Cancer Walk - Charlotte 2011 http://info.avonfoundation.org/goto/Beth
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