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Kwant
22-04-2012, 05:38 PM
Who is up for a quiz? Pictured below is a fancy cut stone, maybe not the best in the world, but do you know what it is? No prizes, but have a guess, post your own pics of one of your favourite stones for us to have a guess at.

I really would like to see some pics of what you all have in your stash :0)

http://farm8.staticflickr.com/7036/7102836923_5c67e0e92b.jpg (http://www.flickr.com/photos/12340604@N02/7102836923/)
Quiz stone (http://www.flickr.com/photos/12340604@N02/7102836923/) by kwant (http://www.flickr.com/people/12340604@N02/), on Flickr

Dennis
22-04-2012, 06:45 PM
A trillion in either light blue topaz, or aquamarine.

I try not to stash stones, so I could only post them already set. Dennis.

Kwant
22-04-2012, 06:58 PM
You are just too good Dennis, it is indeed a topaz :0)

Right well I do not think it is a problem if they are already set so get your *r*e into gear and post a pic :0)


edited to add: though it is not quite a trillian the top in the pic is concave the sides are convex, not quite sure what you would call the cut except of course fancy :0) Heraldic maybe.

Tabby66
22-04-2012, 08:17 PM
I was going to go for aquamarine.......will need to go take some piccies.....

ShinyLauren
23-04-2012, 12:20 PM
Pretty stone - I'd have guessed aquamarine too. I don't think I have anything particularly mysterious to photograph though!

Wallace
23-04-2012, 04:13 PM
3548 you probably know what this is. It has a lot of gold and green mixed together... lovely shine. Too cloudy to get the best pic - it is really tiny, still wondering what to do with it other than keep it in my pot.

some nice gold will bring this out, but mixing it with other stones doesn't seem to work at the moment.

one day......

Kwant
23-04-2012, 04:40 PM
That is a great cut on a pretty stone. I think I know what it is but will wait to hear what other folks think.

I was going to post another that I think might be less than obvious but we too have the worst day of weather, so no pic taking to be done.

Julian
23-04-2012, 06:33 PM
Olivine perhaps ?

Wallace
23-04-2012, 06:47 PM
Olivine perhaps ?

Hi Julian,

it is not an olivine.

mizgeorge
23-04-2012, 07:21 PM
Sphene, or perhaps idocrase?

Dennis
23-04-2012, 08:28 PM
The colour says peridot/olivine, but the cloudiness says emerald. If its not those it's aqua. That's my scatter gun approach. It would make a super mini pendant.
Dennis.

Wallace
23-04-2012, 10:13 PM
lol - this is fun. Time to put your suspenders away!

George - it is indeed a Sphene Yay!

hmmm, super small pendant - sounds like a grand idea :o)

Julian
24-04-2012, 08:48 AM
OK let see what you guys make of this one? I'll add clues as we go along.

Tip: it's meant to deceive !

3549

ps_bond
24-04-2012, 09:30 AM
Now who was it was pointing out that visual appearance isn't a reliable indicator of the stone? :)

Colour tone looks wrong for a sapphire variant (or the ones I've seen), could be a CZ, could be a topaz (although I think there's a slight green tone in there that again I haven't seen in topaz), diamond...?

Julian
24-04-2012, 09:54 AM
Now who was it was pointing out that visual appearance isn't a reliable indicator of the stone? :)

I could not agree more, it goes against my gemological brain. That said the first step in identification is visual inspection.

sapphire can be any color except red (red sapphire is called ruby!) but its not one - that would be too easy :)

3550

It cant be a diamond, there is a shadow in the pavilion (red arrow) a diamond would not do this unless very badly cut or very very small, CZ and Topaz will show this affect

I'll rule out topaz

The purple arrow is the second clue , and why it's not (likely) CZ, and unlikely to be Topaz;

Wallace
24-04-2012, 09:56 AM
is it Alexandrite? I am not good with stones.

Kwant
24-04-2012, 09:57 AM
Ooooh arrows have now appeared :0)

hey Wallace I was going to suggest yours was kryptonite as I went weak when I saw it, but that would imply I am Superman and I am not LOL

Wallace
24-04-2012, 10:03 AM
Ooooh arrows have now appeared :0)

hey Wallace I was going to suggest yours was kryptonite as I went weak when I saw it, but that would imply I am Superman and I am not LOL

I spurted my cuppa when I read that.............lmao......lolololol


I so do not know what to do with it. I have had it for three years and it keeps on appearing - I do have some gold now that I could use to do a micro pendant........... but all those angles, I am afraid I will break it!


still lol- ing!

Julian
24-04-2012, 10:33 AM
is it Alexandrite? I am not good with stones.

Sorry,Alexandrite should turn from green to red, "lab Alexandrite" which normally is synthetic carborundum (sapphire) can be blueish. Like emerald, even the best natural Alexandrite has loop visible inclusions, which in fact contribute to the color change affect. this stone is too clean.

ps_bond
24-04-2012, 11:08 AM
Sorry,Alexandrite should turn from green to red...

Oh go on, it isn't every day you get to use the word pleochroism...

When you mentioned the shadow on the pavillion, were you meaning that with a brilliant cut it should throw light from that surface as readily as the rest?

ShinyLauren
24-04-2012, 11:41 AM
is it Alexandrite? I am not good with stones.

I was going to go for alexandrite too.

Dying to find out what it is now...

eirish
24-04-2012, 12:06 PM
Could it be spinel? Or, hmm, maybe kyanite?

(Just tossing out other blue stones I know of here!)

Julian
24-04-2012, 12:06 PM
Oh go on, it isn't every day you get to use the word pleochroism...

When you mentioned the shadow on the pavillion, were you meaning that with a brilliant cut it should throw light from that surface as readily as the rest?

Yes that's, exactly right, the brilliant cut is designated to exactly that, but its dependent on the refractive index of diamond. You could change the material to sapphire for example, but you would have to change the angles of the cut, this would then look like an odd shaped stone and make it harder to make standard settings.

Strontium Titanate has been used for a diamond stimulant ( but not too often these days) it has the same (almost) refractive index to diamond , and is just about the only confusion possible ( it will fail a thermal diamond probe)

This stone below ( a synthetic sapphire) has been cut like that, but just look at the depth !

3551

Dennis
24-04-2012, 12:09 PM
While you are all deep in thought I'll put on mine which is much easier. This collection of chipped stones lives in the back of a drawer. It should be trashed, really, but I'm too mean. They represent failed rub down settings and to look at them is like a knife in my heart. As you will gather, small squares are the worst. Dennis.

Kwant
24-04-2012, 12:35 PM
Aww the box of shame: are they 3 beryl, tourmaline cab, dark citrine, amethyst and a rhodolite garnet, the bottom left one perhaps another tourmaline?

eirish
24-04-2012, 12:41 PM
I thought the top cab might be labradorite? and the 3 squares peridot? I'd also vote for citrine, garnet, and amethyst but I think I'll guess fluorite for the other green square.

Julian
24-04-2012, 12:41 PM
Could it be spinel? Or, hmm, maybe kyanite?

(Just tossing out other blue stones I know of here!)



Bingo

There are two types of stone that can easily be mass produced, to just about any color buy adding additional elements (iron, titanium, chromium, copper magnesium, cobalt, vanadium etc. ) to the Verneuil process; Sapphire and Spinel (http://en.wikipedia.org/wiki/Verneuil_process) The strange color should make these two ring alarm bells.

This stone is particularly nasty. The purple arrow points to what appears to be double refraction. This should eliminate all singularly refractive stone including diamond and CZ . Many double refractive stone the refraction is so slight you cant see it without polarization (I was lucky to capture it hear) AKA saphire. (http://en.wikipedia.org/wiki/Birefringence)

It should also eliminate spinel, but Synthetic spinel is known for showing anomalous double refraction because of the growing process., which cause internal strain.

The stone is in fact a synthetic cobalt spinel. Under a Chelsea filter the thing looks “radio active” (no pun intended)

RI and SG confirm the diagnosis, but you cant do that from a photo :(

Kwant
24-04-2012, 01:52 PM
To run concurrently with the stones Dennis posted from his box of shame here is the one (well four) that I could not take a picture of yesterday due to no light.

All the same material just 4 different cuts.

http://farm8.staticflickr.com/7059/6963396030_96f25ea1f0.jpg (http://www.flickr.com/photos/12340604@N02/6963396030/)
Quiz stone group (http://www.flickr.com/photos/12340604@N02/6963396030/) by kwant (http://www.flickr.com/people/12340604@N02/), on Flickr

eirish
24-04-2012, 02:56 PM
This stone is particularly nasty. The purple arrow points to what appears to be double refraction. This should eliminate all singularly refractive stone including diamond and CZ . Many double refractive stone the refraction is so slight you cant see it without polarization (I was lucky to capture it hear) AKA saphire. (http://en.wikipedia.org/wiki/Birefringence)

It should also eliminate spinel, but Synthetic spinel is known for showing anomalous double refraction because of the growing process., which cause internal strain.

Wow, I'm chuffed that I guessed it correctly, but being a physicist I'm really fascinated by the explanation. I've done outreach activities with schoolchildren on strain-induced birefringence using two pieces of polaroid film, an overhead projector, and some bits of clear plastic. I bet you could use 3D glasses as well - must try that when I get home.

medusa
24-04-2012, 04:18 PM
Bingo

There are two types of stone that can easily be mass produced, to just about any color buy adding additional elements (iron, titanium, chromium, copper magnesium, cobalt, vanadium etc. ) to the Verneuil process; Sapphire and Spinel (http://en.wikipedia.org/wiki/Verneuil_process) The strange color should make these two ring alarm bells.

This stone is particularly nasty. The purple arrow points to what appears to be double refraction. This should eliminate all singularly refractive stone including diamond and CZ . Many double refractive stone the refraction is so slight you cant see it without polarization (I was lucky to capture it hear) AKA saphire. (http://en.wikipedia.org/wiki/Birefringence)

It should also eliminate spinel, but Synthetic spinel is known for showing anomalous double refraction because of the growing process., which cause internal strain.

The stone is in fact a synthetic cobalt spinel. Under a Chelsea filter the thing looks “radio active” (no pun intended)

RI and SG confirm the diagnosis, but you cant do that from a photo :(

aaaah and I thought it was very pretty!:">

Kwant
24-04-2012, 05:09 PM
As a by the by Dennis, I saw some really quite nice pendants the other day which were simple silver frames in which had been set (presumably with glue) crushed gemstones or chips, might be a way of using your box of shame without the agony of seeing them go to waste.

Here is a link to one that I saw http://www.etsy.com/listing/88980483/gemstone-pendant-mosaic-opal-peridot-and

Wallace
24-04-2012, 05:39 PM
As a by the by Dennis, I saw some really quite nice pendants the other day which were simple silver frames in which had been set (presumably with glue) crushed gemstones or chips, might be a way of using your box of shame without the agony of seeing them go to waste.

Here is a link to one that I saw http://www.etsy.com/listing/88980483/gemstone-pendant-mosaic-opal-peridot-and

best NOT to glue my sphene! lol

I love the grey blue stones. Especially the one bottom right Cornelius. Near knee buckling moment. lol

Julian
24-04-2012, 05:46 PM
Hear is a nice link for the natural version http://www.sinhalite.com/cobalt-spinel.htm

Kwant
24-04-2012, 05:50 PM
The last pic the macle crystal is just lovely.

Wallace
24-04-2012, 05:52 PM
The last pic the macle crystal is just lovely.

it is delish - probably much nicer than that old Sphene:-p

Julian
24-04-2012, 05:57 PM
As a by the by Dennis, I saw some really quite nice pendants the other day which were simple silver frames in which had been set (presumably with glue) crushed gemstones or chips, might be a way of using your box of shame without the agony of seeing them go to waste.

Here is a link to one that I saw http://www.etsy.com/listing/88980483/gemstone-pendant-mosaic-opal-peridot-and

I have to admit its quit pretty , but the description ; "The mosaic was created with natural hand-cut opal, peridot and iolite" :rofl:

Kwant
24-04-2012, 05:58 PM
Hahhahah yes Julian I did not believe that for one moment :0)

I knew it was a sphene as I am a bit of a fan of them, just did not say at the time coz well the minute I saw it I knew and that would have been spoiling things :0)

Julian
24-04-2012, 06:17 PM
I think I'll guess fluorite for the other green square.

From what I can see, there is a large crack, which is very similar to ones I have seen in aquamarine and citrine. It looks badly scratched, I gues it was no like that when bought, an the scratches look more than setting damage. My guess would be that it came from the other stones in the box. So soft, the others are not that scratched, the two quartz and peridot are of similar hardness.

The green screams iron, asuning the color is not from a color center (shared electron).

I am guessing, I can't see anything I would consider conclusive

Julian

The candidate that comes to mind is beryl, but fluorite is also a good guess.

Dennis
24-04-2012, 08:15 PM
I thought the top cab might be labradorite? and the 3 squares peridot? I'd also vote for citrine, garnet, and amethyst but I think I'll guess fluorite for the other green square.

Yes, Yes, Yes, but the other green square is green tourmaline. As you are such an active and valued member, could we give you a first name, eirish?

Wallace
24-04-2012, 08:28 PM
I knew it was a sphene as I am a bit of a fan of them, just did not say at the time coz well the minute I saw it I knew and that would have been spoiling things :0)

you did say you would give others a chance - and George managed to pip in. :)




Yes, Yes, Yes, but the other green square is green tourmaline. As you are such an active and valued member, could we give you a first name, eirish?

I believe, from the latest comp, I saw that it is Elynor :)

Dennis
24-04-2012, 08:41 PM
As a by the by Dennis, I saw some really quite nice pendants the other day which were simple silver frames in which had been set (presumably with glue) crushed gemstones or chips, might be a way of using your box of shame without the agony of seeing them go to waste.
Here is a link to one that I saw http://www.etsy.com/listing/88980483/gemstone-pendant-mosaic-opal-peridot-and

Thank you Kwant. This re-visits a past thread of mine, because when I came to do just that, I shirked it and used Swarovski crystals instead. I shall probably grind these up and put them in someone's sandwiches. Get ready to send me a fruit cake with a hacksaw in it. Dennis

Kwant
24-04-2012, 09:27 PM
Ah yes now that I see the pic I remember that piece. Well I am quite a good cake maker so just let me know where you end up, though for a gent like you I suspect it will be somewhere like Ford and who knows it might make a pleasant break from Central London :0)

eirish
25-04-2012, 10:45 AM
I believe, from the latest comp, I saw that it is Elynor :)
That's me. :)

Elynor

Wallace
25-04-2012, 10:09 PM
That's me. :)

Elynor
Hi again Elynor :)
:~: