need help to gem experts of this forum

[Tariq wali]

i have a yellow stone ,badly cut, cutting not symmetrical , uneven facets, lusturous but blemeshes on surface .more then 12 ct, most of the facets are abraded ,

my question is that , cutting of this stone belongs to old era ? or cut by a trainee cutter of this era ? these facets are abraded or unfinished ? table of the stone is diffrent . i am far from the specific gravity facilities at this moment.

these all questions raises when i used UV pen light on the stone , yellow topaz or yellow sapphire also behave like that in UV light ?

while i thought ,this is yellow sapphire , UV test confused me , so i need ur help to go forward .

 

[Tariq wali]

facing some problem to post more pictures , hope soon

 

[Tariq wali]

feather i think

 

[Tariq wali]

unable to post more pic here , look behave in UV pen light

**edited by moderator. please upload photos to forum directly**

 

[iLander]

What is that?

With that amount of abrasion, even on the bottom, my first guess would be glass. But sapphire does come in a lot of colors, so maybe. But sapphire is very hard, and would be tough to abrade. Unless it was very old, over 100 years maybe. Is it old?

There are a lot of yellow stones that are very soft. I can't remember them, maybe another poster will think of some.

But it's a guess and everyone will come here and tell you to take it to a lab for testing. It's too hard to guess from a photo.

Maybe the history of the stone will help. Where did you get it and what is it's story?

 

[Tariq wali]

iLander, thanks for reply

i am also suspicious about the history of this stone , look at the table of the stone its looking like the table of 1700

 

[pregcurious]

It's not possible for us to identify your stone from pictures. If it were me, I would submit it to a reputable gem laboratory. If you are in the US, you can send it to AGL in New York and get a short gem report for $60.

http://aglgemlab.com/

If you are not in the US, please give us your general location and hopefully someone can suggest a lab.

 

[Roger Dery]

I believe it will be determined to be corundum. The facets are too flat to end up as something much softer [as in glass]. The luster exhibited is also too high for low Mohs Hardness rating. The exhibited damage is typical long-term "paper wear". [even though the paper it may have been stored in didn't create the abrasive damage].

Paper wear is a gem trade term referring to when gems have been placed together in a 'gem paper' for long periods of time. Years ago when traveling gem dealers carried their goods around in a wooden or metal 'gem box', the gems were neatly placed in stone papers. Corundum, even with hardness 9, when bounced around with other hardness 9 gems will eventually give way.

With the advent of internet sales, the concept of traveling gem salesmen has gone away. And, therefore, we seldom see paper wear situations anymore. However, if one was to visit some of the old-time gem outfits on 47th Street or 5th Ave in the jewelry district in NYC you would find paper wear still exists!

Cost on performing basic Gem ID and Enhancement report will be $135 for fancy Sapphire over 10cts.
http://aglgemlab.com/pricelist/

Hope someone finds this useful.

 

[pregcurious]

Thanks, Roger, that was very educational. Also, thanks for correcting the price I posted. I did not realize it was so big.

Tariq, I hope you have a sapphire there! It's a very pretty color and hard to find in an untreated sapphire. Please let us know if you determine what it is.

 

[digdeep]

I believe it will be determined to be corundum. The facets are too flat to end up as something much softer [as in glass]. The luster exhibited is also too high for low Mohs Hardness rating. The exhibited damage is typical long-term "paper wear". [even though the paper it may have been stored in didn't create the abrasive damage].

Paper wear is a gem trade term referring to when gems have been placed together in a 'gem paper' for long periods of time. Years ago when traveling gem dealers carried their goods around in a wooden or metal 'gem box', the gems were neatly placed in stone papers. Corundum, even with hardness 9, when bounced around with other hardness 9 gems will eventually give way.

With the advent of internet sales, the concept of traveling gem salesmen has gone away. And, therefore, we seldom see paper wear situations anymore. However, if one was to visit some of the old-time gem outfits on 47th Street or 5th Ave in the jewelry district in NYC you would find paper wear still exists!

Cost on performing basic Gem ID and Enhancement report will be $135 for fancy Sapphire over 10cts.
http://aglgemlab.com/pricelist/

Hope someone finds this useful.

This 'someone' found it useful! Roger.....if you are still here......does the facet page that the OP showed resemble the stone faceting for a possible reference? Or do you see anything else in the facet's that you can educate us on? Thanks much!

 

[minousbijoux]

...and I have a question for you too, Roger. What did you mean by: "The facets are too flat to end up as something much softer [as in glass]"? Thank you.

 

[cm366]

Great explanation, thanks Roger!

Minou, I suspect Roger means that the degree of abrasion demonstrated would have caused the facets to round off if the material were less hard than corundum, but I eagerly await his clarification!

 

[Edward Bristol]

Yes, and also parcels of gems with the same hardness carried around and nervously squeezed and prodded during the negotiation process.

"If you don't stop rolling that bag between your fingers I will not buy it at any price."

"why?????"

 

[Roger Dery]

from DigDeep

This 'someone' found it useful! Roger.....if you are still here......does the facet page that the OP showed resemble the stone faceting for a possible reference? Or do you see anything else in the facet's that you can educate us on? Thanks much!

Hi,
No, I don't think so regarding the possible reference.

The facet arrangement on the above yellow gem is a a very simple design. One often used on Sri Lankan gems from the late 1880's to mid 1900's. Today, I look for these at gem shows (especially from retiring or older gem dealers) like in Tucson. I will review their older/ancient goods that they may have had for a very long time, show heavy paper wear, and are probably a bargain considering where things are going today.

Sidenote: about 10 years ago while visiting one of these historic gem firms (from New Jersey, in business from just after WWII) I found two natural Spinels. They were both over 4cts, very gemmy blue, badly constructed, highly abraded - and in the 'cheap pile'. In speaking with the owner he said "it was part of a larger parcel his dad purchased 'eons ago' and they were no longer interested in them - and could I please take them off their hands". I spent a fair amount with them that day in 're-cutters' and picked up the blue Spinels for $40/ct. They recut into 2-1/2ct gems in a square emerald cut and a cushion. They both sold within weeks to two different jewelers for the going rate for top Spinels.

All that being said, one has to know what they are doing, and have an understanding when an existing gem is a good candidate for recutting - as this is more art than science. *not something that can be explained in 2 sentences or 2 paragraphs [I know someone is going to ask ]

 

[Roger Dery]

...and I have a question for you too, Roger. What did you mean by: "The facets are too flat to end up as something much softer [as in glass]"? Thank you.

Minou,
Corundum has the capacity to have very flat facets - even with older technology. Glass on the other hand generally does not. Especially so when using much older technology as was probably used on this gem. And, on glass, the facet junctions seldom show sharp (or as some say, crisp) edges. The lower hardness just doesn't allow for this too happen. I'm sure, with modern tech one "could" create very sharp facets on glass, but why would one spend the extra time?

The abrasions seen on the pavilion of this cushion are consistent with corundum touching corundum (or another very hard substance). There are hundreds of tiny chips and micro-chips having the facet junctions appear as a roughed-up line.

If this comes back as something different than corundum, I will be very surprised.

 

[Roger Dery]

Great explanation, thanks Roger!

Minou, I suspect Roger means that the degree of abrasion demonstrated would have caused the facets to round off if the material were less hard than corundum, but I eagerly await his clarification!

cm366 -
yes, but generally much less hard than corundum. Facet junction rounding becomes more noticeable as the hardness decreases. And is usually obvious on hardness 5 and lower.

 

[Tariq wali]

close look

 

[iLander]

Is anybody else seeing rainbows? I see a lot of dispersion in these photos.

I'm starting to wonder if it's possibly a diamond?

If bag wear (usually I think of collectible coins when I hear this phrase) could cause this much damage, I wonder if it could have been a bag of diamonds? Especially if it's been rolling around in the bag for decades.

I think I brought this up in another thread: what happened to all those colored diamonds they found in the old days, when only white was accepted? Where did they go? They had to go somewhere.

Honestly, I would try to get this puppy to a lab. We just had another poster whose "brown topaz" turned out to be a gigantic brownish diamond.

 

[JewelFreak]

In the photos on a lighter surface, it doesn't show a lot of brown secondary on my monitor, a nice clean yellow, maybe some green in one photo. What a nice thing for someone to bring a stone that probably is something special! Hope the OP can get it to a lab quickly -- and please update us on their findings.

Really interesting info, Roger -- thanks for the benefit of your experience!

--- Laurie

PS -- iLander -- I missed the brown diamond thread -- where is it? Thanks!

 

[iLander]

In the photos on a lighter surface, it doesn't show a lot of brown secondary on my monitor, a nice clean yellow, maybe some green in one photo. What a nice thing for someone to bring a stone that probably is something special! Hope the OP can get it to a lab quickly -- and please update us on their findings.

Really interesting info, Roger -- thanks for the benefit of your experience!

--- Laurie

PS -- iLander -- I missed the brown diamond thread -- where is it? Thanks!

It is here: [URL='https://www.pricescope.com/community/threads/brown-diamond-vs-topaz-its-2-sad-ruby-friends.193220/']https://www.pricescope.com/community/threads/brown-diamond-vs-topaz-its-2-sad-ruby-friends.193220/[/URL]

It's a pretty bizarre thread . . .

 

[iLander]

I wonder if it's a sphene? Those are pretty soft, and they shoot out rainbows . . .

I'm kind of enjoying this detective game . . .

 

[digdeep]

Tariq......is this information helpful? You have some more detective work ahead of you, but what an adventure! Please let us know what you find out.....

Roger......Thank you for your comments! It all makes sense when I think about it, but in the broad world of gems this is the kind of thing that can be easily and broadly overlooked or discounted.
I enjoy having the provenance of a gem (specific or general)........I'm guessing Tariq may have more knowledge about the background of this gem?

 

[JewelFreak]

Thanks, iLander -- I read the beginning of that but didn't see the part after she got reports. I guess we never heard the answer to the question on vivid rating.

Anyway, this stone here is another interesting (& I hope also happy) puzzle.

 

[minousbijoux]

from DigDeep

This 'someone' found it useful! Roger.....if you are still here......does the facet page that the OP showed resemble the stone faceting for a possible reference? Or do you see anything else in the facet's that you can educate us on? Thanks much!

Hi,
No, I don't think so regarding the possible reference.

The facet arrangement on the above yellow gem is a a very simple design. One often used on Sri Lankan gems from the late 1880's to mid 1900's. Today, I look for these at gem shows (especially from retiring or older gem dealers) like in Tucson. I will review their older/ancient goods that they may have had for a very long time, show heavy paper wear, and are probably a bargain considering where things are going today.

Sidenote: about 10 years ago while visiting one of these historic gem firms (from New Jersey, in business from just after WWII) I found two natural Spinels. They were both over 4cts, very gemmy blue, badly constructed, highly abraded - and in the 'cheap pile'. In speaking with the owner he said "it was part of a larger parcel his dad purchased 'eons ago' and they were no longer interested in them - and could I please take them off their hands". I spent a fair amount with them that day in 're-cutters' and picked up the blue Spinels for $40/ct. They recut into 2-1/2ct gems in a square emerald cut and a cushion. They both sold within weeks to two different jewelers for the going rate for top Spinels.

All that being said, one has to know what they are doing, and have an understanding when an existing gem is a good candidate for recutting - as this is more art than science. *not something that can be explained in 2 sentences or 2 paragraphs [I know someone is going to ask ]

Once again, so impressed, Roger. Of course you would go to gem shows looking for the old discarded ugly ducklings and of course it would take years to train your eye to know what to seek! It makes perfect sense. How exciting to make a discovery like your blue spinels. And thank you for your explanation. It was the use of the word "flat" that was throwing me off, and I realize that you
were using the word to mean, well, literally flat or shallow angled?

 

[pregcurious]

What about chrysoberyl?

 

[Roger Dery]

Once again, so impressed, Roger. Of course you would go to gem shows looking for the old discarded ugly ducklings and of course it would take years to train your eye to know what to seek! It makes perfect sense. How exciting to make a discovery like your blue spinels. And thank you for your explanation. It was the use of the word "flat" that was throwing me off, and I realize that you were using the word to mean, well, literally flat or shallow angled?

Hi Minou - regarding my use of the word "flat".... I was referring to the individual facets, in that, they were not exhibiting a curvature either slightly concave, or slightly convex. Meaning, given when they were likely rendered, that the individual facets were quite flat.

Assuming this is actually a gem that was faceted a long time ago (and I believe this to be true), flatness of facets was something a lapidary would aspire to. And given the equipment constraints of the time, it would be a difficult task to accomplish. It still is today.

In today's faceting equipment world though, we have many tools at our disposal that can assist us with creating very flat facets that increase brightness AND contrast in a faceting design. When the above yellow gem was produced, flatness of facets was not their main concern. This is most noticeable by reviewing the table on most any type of large gem from that era.

*sidenote; when I was traveling in Sri Lanka in 1981, on my way from Colombo to Ratnapura I exited my bus several kilometres before my normal destination. Stopped and visited a gem cutting operation for a few hours. During our conversation I asked the proprietor how long had his people been using their machines? He said they arrived just after WWII ended. So at that point they'd been in operation for well over 30 years.

 

[Roger Dery]

What about chrysoberyl?

Chrysoberyl is another good possibility. We won't know till he takes it to a laboratory. Until then, just playing with theory!

 

[Tariq wali]

thank you very much roger , so kind of you for usefull knowledge , and thanks for all others too those repling me , i will go for it to a major lab , i have a visit to bangkok hopfully in next 20 days . so pls advise me which lab will be preferable in bangkok . and result will discus here .

 

[kenny]

Since diamond was mentioned you can take it to a jeweler or pawn shop.
Ask them to use their diamond tester on it.

I cringe every time I hear about gems thrown together to scratch each other.
I'm astonished that this happens.

 

[T L]

It could be quartz too. I don't think diamonds show that much facet abrasion.