Ever heard of UV garnet?

[gemandjewelrylover]

I was wondering if anybody had ever heard of UV garment? My jeweler recently got a few stones in. They are a very pretty light mint green color, and under black light they turn to a Peachy padparadscha sapphire color. I looked it up on the Internet, but I couldn't find anything about them. They come from Tanzania apparently. Sounded to me like the mine might already be played out. I asked my jeweler if they were color change garnets, and he said no, they weren't, because they only change color under black light. So I was just wondering if anybody here on Pricescope knows anything about them? I'm posting a couple pictures below. In two of the pictures the color is fairly accurate, and in two of the pictures it's not so accurate, I will note that in the comments under the photos.

 

[gemandjewelrylover]

One more color change picture

 

[chrono]

Some green gossular garnets will fluorescence a weak orange under long UV or yellow under short UV light. The reason for this is due to chromium content in the garnet, which typically fluorescences red but the colour perception (and its low amount/weakness) makes it look pink orange. These green garnets are only mined in the Tanzania region and lighter garnets are often times called mint garnet whilst the darker ones are called tsavorite.

 

[katharath]

Yes, I have several mint garnets and they all do this

 

[gemandjewelrylover]

Hmmmm...maybe it's just a name thing then. I guess that explains why I couldn't find anything! Thank you!

 

[T L]

Hmmmm...maybe it's just a name thing then. I guess that explains why I couldn't find anything! Thank you!

It's a goofy name thing I think. You can only see the fluorescence with a UV light, not in the sun, so why they call it UV garnet is to me. In other words, you can't really enjoy the color shift unless you go in a darkish room and shine a UV light on it.

I have some mint garnets that do this color shift under a UV light as well.

 

[gemandjewelrylover]

Ah, mystery solved. Thank you very much!

 

[LoversKites]

Didn't know this before... what an interesting effect.

 

[minousbijoux]

So would darker grossulars - namely tsavorites - show the same effect?

 

[T L]

So would darker grossulars - namely tsavorites - show the same effect?

Some, not all. Not all mint garnets show this effect either.

 

[LD]

Many gemstones exhibit fluorescence - which is what yours do. However, I've never seen them marketed as UV anything and to be honest it sounds like a silly gimmick to fool people into thinking they are buying something rare (shopping telly channels are the worse for this)! Your pendant is very pretty and it's a mint garnet (which sounds much more yummy than calling it a UV garnet)

 

[chrono]

If it is coloured by vanadium, it is unlikely to fluorescence. If coloured by chromium, then it will fluorescence. This applies to both mint garnet and tsavorite.

 

[minousbijoux]

All makes sense. I wouldn't mind any of my grossulars turning a nice padparadscha/pink type color under UV...

 

[1001smiles]

OK, I was curious, so I shined a UV light on a box of Merelani mint garnets, looks like some have more fluorescence than others. Too bad my camera has trouble with greens, but you get the idea.
I think "UV garnet" is just a marketing thing...

 

[gemandjewelrylover]

So these stones can be called Merelani mint garnets, mint garnets, and grossular garnets? And now UV garnet...or at least here in Japan. Lol. I don't think it's a gimmick, but it looks like these stones go by a lot of names. 1001smiles, were yours all mined from the same place?
Or some in one place and others in another? Would that explain why some fluoresce and some don't? Or same place, different time?
Just wondering.

I didn't buy them, btw....just thought they were interesting so I thought I'd ask.

 

[LD]

So these stones can be called Merelani mint garnets, mint garnets, and grossular garnets? And now UV garnet...or at least here in Japan. Lol. I don't think it's a gimmick, but it looks like these stones go by a lot of names. 1001smiles, were yours all mined from the same place?
Or some in one place and others in another? Would that explain why some fluoresce and some don't? Or same place, different time?
Just wondering.

I didn't buy them, btw....just thought they were interesting so I thought I'd ask.

Fluoresence is due to chemical makeup. Some will have it, some won't. It was explained by Chrono further up this thread.

In terms of the names, you're not quite right. Merelani Mint Garnets are from Merelani (which is a different location from others). Mint garnet is just a descriptor to distinguish from orange, red, blue garnets etc. Grossular garnet is the correct name for a green garnet. UV garnet is not a name - it's a marketing gimmick.

 

[chrono]

The correct name for the garnet is green grossular garnet, being that they are a calcium-aluminium mineral species of the garnet gemstone group. It is called green to differentiate it from the brown (hessonite), red and yellow grossular garnet in the same family. Green grossular garnets are mined only in Kenya and Tanzania.

The darker green grossular garnet was coined Tsavorite by the Tiffany company president in honor of Kenyan Tsavo National Park. In an effort to better promote its lighter green grossular garnet sibling, it came to be known as mint garnet. Because these are generally mined in the Merelani hills region, they are sometimes also referred to as Merelani mint garnet, as a reference to their origin.

UV garnet is clearly a marketing gimmick the same way blue fluorescent diamonds are known as blue-white diamonds.

As explained above, trace amounts of chromium and vanadium are what gives these grossular garnets their green colouration. Those coloured by chromium will show fluorescence. Those coloured by vanadium will be inert. Origin (or mine location) or the time it was mined has no bearing on whether a particular green grossular garnet fluorescences or not.

 

[gemandjewelrylover]

Ok, thank you all. I learn something new every day on Pricescope from all of the CS aficionados and gurus!

 

[VapidLapid]

there is a garnet species that might be abbreviated UV. Uvarvrite. I have only seen it offered as mineral specimens. They seem to be tiny and form in a druzy-like coating.


http://www.johnbetts-fineminerals.com/jhbnyc/gifs/59037.htm


http://en.wikipedia.org/wiki/Uvarovite

 

[gemandjewelrylover]

there is a garnet species that might be abbreviated UV. Uvarvrite. I have only seen it offered as mineral specimens. They seem to be tiny and form in a druzy-like coating.


http://www.johnbetts-fineminerals.com/jhbnyc/gifs/59037.htm


http://en.wikipedia.org/wiki/Uvarovite

Wow, they say it's one of the rarest green garnets out there, but yet the cost of that specimen at John Betts is only $90. Is it because it's in Druzy–type stone as opposed to a translucent gemstone? I guess rare doesn't always equal expensive.

 

[VapidLapid]

Rarity is not the only factor. The size of those individual crystals is under one millimeter, not even big enough for a 1 point melee. If the mineral is too small for use as a gem or not gem quality then the only market is as a mineral specimen to collectors of such, and priced accordingly.

 

[gemandjewelrylover]

Ah, I see. It's hard to tell their size from the pictures...as is usually the case with all gemstone pictures, as we all know. Gems always look so big in photos... Thanks for the info!

 

[LoversKites]

Rarity is not the only factor. The size of those individual crystals is under one millimeter, not even big enough for a 1 point melee. If the mineral is too small for use as a gem or not gem quality then the only market is as a mineral specimen to collectors of such, and priced accordingly.

Have you or anyone else seen a faceted example of uvarvrite garnet? Even if it's teeny tiny?

 

[chrono]

Here's a 2 cm piece here but it's so rare that it is doubtful anyone would want to facet it. The largest pieces (still small at 1 mm) seems to be more commonly found in Finland than elsewhere.

 

[T L]

Here's a 2 cm piece here but it's so rare that it is doubtful anyone would want to facet it. The largest pieces (still small at 1 mm) seems to be more commonly found in Finland than elsewhere.

picture????

 

[LoversKites]

Here's a 2 cm piece here but it's so rare that it is doubtful anyone would want to facet it. The largest pieces (still small at 1 mm) seems to be more commonly found in Finland than elsewhere.

picture????

Yes, please show us a pic. Really 2cm? Amazing.

 

[T L]

Here's an 8mm one, which is unheard of.

http://www.minfind.com/mineral-17862.html

 

[chrono]

Oops, sorry about missing link.
http://www.mindat.org/gallery.php?cform_is_valid=1&min=4125&cf_pager_page=1

As you can see, even though the material might be large enough, they are just too opaque to facet.

 

[LoversKites]

Oops, sorry about missing link.
http://www.mindat.org/gallery.php?cform_is_valid=1&min=4125&cf_pager_page=1

As you can see, even though the material might be large enough, they are just too opaque to facet.

No problem, thanks for coming back to post the link. Whoa, they have some amazing specimens. Hopefully one day I'll be able to appreciate mineral specimens as much as faceted gems.

 

[BlingObsession]

I have a golden yellow grossular garnet from Brad which changes to the most amazing orange/pink colour under UV. Sadly I can't photograph it but here's a picture of the ring and a picture to demonstrate the colour change (stolen from the OP ). My UV colour change is more intense than in the photo.

The stone is actually much more yellow in real life - not brown all. It sparkles beautifully and I love it.

Setting by Jeff Davies.