17.1ct Cut Zircon - Thoughts?

[oz_prospector]

Hi there!

I was recently gifted/inherited this stone and just trying to find out if it's worth sending in to get a certified evaluation done. The only info I received with the stone was that it's 17.1ct zircon.

Here are some pics I've taken -- note that the white paper brings out the blue/green quite a bit more than visible with naked eye, which is a very slight blue tinge -- otherwise on casual inspection it looks clear/white. Any thoughts much appreciated!

 

[dk168]

Based on the photos alone, I do not believe it is a Zircon as I cannot see any double refraction which is indicative for Zircons.

Can't tell what else it could be as there are a number of CSs that could look like it.

DK

 

[oz_prospector]

Ahh! Hmm... in that case I'm thinking I should try and do a specific gravity test to narrow the possible options? I've done an SG test before to calculate gold weight of a specimen I found prospecting -- just have to refresh my memory on the process and I'll give it a go.

Thanks!

 

[Bron357]

With the blue green and yellow, could it be a parti sapphire? Very pretty in any regard.
How exciting.

 

[T L]

Based on the size and low refraction, it’s probably a quartz, like prasiolite.

 

[pwsg07]

Looks like an aquamarine to me.

 

[oz_prospector]

Hmmm.... so I did a SG test, albeit a proper "macgyver" job using whatever I could find which gave me a SG result of 3. However certainly not convinced it was an accurate measurement so I'll try and find someone around my area that is properly equipped to do refraction/SG tests... for the time being it's a guessing game... hoping it's more than just quartz!

 

[Tartansparkles]

Does it throw off rainbows when it catches the light? If it is a zircon I'd love to know how much a stone of that size dazzles! (To check for double refraction my jeweler draw a line on a piece of paper and viewed the line through the stone and hey presto, two lines appeared. Might be something else to try if you haven't done so already).

 

[oz_prospector]

Oh it's that easy? Does it matter which part of the crystal you look through?

Edit: Just had a try and assuming I'm looking through it on the right angle it does appear to have some refraction but it's not consistently clear as it wiggles around.

Oh and not seen any rainbows on it

 

[GliderPoss]

Could it be Topaz?

 

[oz_prospector]

Could it be Topaz?

Yeah if it's not zircon then topaz would be most likely I think... still crossing my fingers that it's zircon or aquamarine but I'm a little pessimistic now. I'm taking it to a gemologist to get it tested and hopefully identified later today/tomorrow -- will update with results!

 

[oz_prospector]

Yeah so took it to a gemologist who did a quick refraction test and she's, pretty certain, it's topaz. Said it's a nice piece as it doesn't appear to be heat treated, so it's a nice natural subtle blue -- but alas, not Zircon. :'(

 

[Bluegemz]

Well, a natural blue topaz is lovely too! I think it has a beautiful, almost aquamarine like color with a little bit of green in it. Very subtle color which IMO is elegant.

 

[shelovesinclusions]

It's really pretty and isn't it unusual for topaz to be unheated? Very cool stone to get as a gift. What are your plans? It would be pretty in a pendant.

 

[dk168]

Natural unheated Topaz are not difficult to find, and I am fortunate to have 2 cut by Doug Menadue of Bespoke Gems from a massive rough a few years ago.

DK

 

[oz_prospector]

Yeah it's still a very nice piece and I'll perhaps have it set as a pendant or something one day -- though not sure if the green/yellow tinge you see in the pics is really part of the stone or just reflection of the metal on the tape measure or something because it only appears a feint blue when looking at it in my fingers.

Just to be certain I decided to do another SG test, this time fine-tuning my testing setup and making it as accurate as possible, and I got a SG of 3.37 which falls right in line with what I'd expect from Topaz (within margin for error) -- so at least now my mind is at ease with confidence that I know what it is.