4 Carat Colour Shift Sapphire Brooch

[mina78]

I want to share a very recent purchase I made while on holiday in Derbyshire.

Although I’ve yet to have this stone lab tested I’m fairly certain it’s a natural OEC cut 4 carat colour shift (blue to purple) sapphire stone mounted in a 3 inch long Art Nouveau 15ct and moonstone brooch.

It caught my eye because it was very poorly labelled and the seller didn’t seem to know what they had. I was very happy to pay £248 for it which is just over its gold scrap value, especially as it included a high quality antique box and 15ct security chain.

I suspect the brooch dates from 1900-1910 judging by its style and construction.

Would love to hear everyone’s thoughts on this piece- I’ve never seen a brooch quite like this before and it caught my eye immediately.

 

[Rfisher]

It’s a lovely brooch.

I’m not an expert - so I’m curious what points of construction on this brooch you see that leads you to believe it’s age?

I wouldn’t have pegged this stone as natural mined sapphire - but again - I’m no expert.
Hope you update this thread on the results of the lab testing results or any other evaluations you have done.

 

[Autumn in New England]

Always such a pleasure to see a brooch on this forum! I don't think they get enough love, although I feel like there is a new and recent appreciation. Anyway... very pretty piece. I am curious... what does the "15c" hallmark mean? Is that a European stamp similar to our 14k gold alloy? TIA!

 

[mina78]

Always such a pleasure to see a brooch on this forum! I don't think they get enough love, although I feel like there is a new and recent appreciation. Anyway... very pretty piece. I am curious... what does the "15c" hallmark mean? Is that a European stamp similar to our 14k gold alloy? TIA!

If my memory serves me correctly 15ct was a gold standard used in the UK between 1850 (ish) and was discontinued in 1932 in favour of the more popular US 14ct purity. 15ct is 62.5% gold purity, whereas 14ct is 58.5%.

 

[Autumn in New England]

If my memory serves me correctly 15ct was a gold standard used in the UK between 1850 (ish) and was discontinued in 1932 in favour of the more popular US 14ct purity. 15ct is 62.5% gold purity, whereas 14ct is 58.5%.

Thank you! How interesting!! Neat way of dating the piece as well. Enjoy your new pretty.

 

[ItsMainelyYou]

Oh, I think it may be natural, I do wonder if it may actually be a shifty spinel. I have one with inclusions like that. I can't believe you found an OEC cut in a colored stone! I'm jealous and would love to find one myself! Can't speak to the age of the mount- if it is, it was well protected because the moonstones are in good shape.
I would love to hear how testing would come out.

 

[pokerface]

What on earth are these inclusions? They look more like actual fibers than "fibrous."

 

[Autumn in New England]

What on earth are these inclusions? They look more like actual fibers than "fibrous."

I saw that and was wondering if it was debris behind and under the mounting? It looks like it has not yet been cleaned.

 

[ItsMainelyYou]

What on earth are these inclusions? They look more like actual fibers than "fibrous."

I don't know what those are exactly, I have a spinel with weird fiber-like inclusions but they're white and there weren't as many. They were noted as rutile needles.
Though, a good clean is in order to make sure.

 

[Autumn in New England]

I don't know what those are exactly, I have a spinel with weird fiber-like inclusions but they're white and there weren't as many. They were noted as rutile needles.
Though, a good clean is in order to make sure.

Good point... and rutile is definitely found in sapphire. But the needles are usually very straight/angular (not wiggly and wispy). I still think a nice cleaning with a soft brush, warm water, and mild detergent is needed, as you said.

 

[glitterata]

Next time you go on holiday in Derbyshire, please take me along in your suitcase. I promise to be very quiet. I will only come out when you go jewelry shopping.

 

[CaseyLouLou]

It’s a fun treasure and it sounds like you got a good deal. My guess is it’s a synthetic alexandrite.

 

[mina78]

What on earth are these inclusions? They look more like actual fibers than "fibrous."

After some research I believe they’re fibrous pargasite inclusions.

Large Pargasite Inclusion in Kashmir Sapphire | Gems & Gemology

Unusually large prismatic pargasite inclusions observed in a Kashmir sapphire submitted to the Carlsbad lab for origin determination.

www.gia.edu

 

[mina78]

I saw that and was wondering if it was debris behind and under the mounting? It looks like it has not yet been cleaned.

These are definitely inclusions and not debris/fluff etc.

 

[pokerface]

I really don't think so. The second photo, definitely not. Rutile, maaaybe, but I am deeply skeptical. I think it's more likely to be material that became trapped during a manufacturing process. Do you have a way to take better photos of the inclusions?

After some research I believe they’re fibrous pargasite inclusions.

Large Pargasite Inclusion in Kashmir Sapphire | Gems & Gemology

Unusually large prismatic pargasite inclusions observed in a Kashmir sapphire submitted to the Carlsbad lab for origin determination.

www.gia.edu

 

[mina78]

I really don't think so. The second photo, definitely not. Rutile, maaaybe, but I am deeply skeptical. I think it's more likely to be material that became trapped during a manufacturing process. Do you have a way to take better photos of the inclusions?

Perhaps they’re simply feather inclusions?

I’ll try and take some better photos and post them here.

 

[pokerface]

Bump!!

 

[mina78]

Bump!!

Update:
I've handed this brooch over to Stephen Kennedy who runs 'The Gem & Pearl Lab' in Hatton Garden, London, so I'll update this thread with the results of this test once I hear back from Steve. He has a 2-3 week backlog so it may be a while until this thread gets updated, but you'll all be the first to know.

I'm crossing my fingers for the 1 in a billion chance it's natural Alexandrite

 

[CaseyLouLou]

Update:
I've handed this brooch over to Stephen Kennedy who runs 'The Gem & Pearl Lab' in Hatton Garden, London, so I'll update this thread with the results of this test once I hear back from Steve. He has a 2-3 week backlog so it may be a while until this thread gets updated, but you'll all be the first to know.

I'm crossing my fingers for the 1 in a billion chance it's natural Alexandrite

Could be! The color change is similar and it has inclusions. Good luck!

 

[canuk-gal]

HI:

I love these jewellery mystery threads! Hope Santa comes early for you! Whatever it turns out to be , it is (still) very pretty

cheers--Sharon

 

[pokerface]

Natural alexandrite is not blue - at least, certainly not in an antique piece. So it's not that.

Update:
I've handed this brooch over to Stephen Kennedy who runs 'The Gem & Pearl Lab' in Hatton Garden, London, so I'll update this thread with the results of this test once I hear back from Steve. He has a 2-3 week backlog so it may be a while until this thread gets updated, but you'll all be the first to know.

I'm crossing my fingers for the 1 in a billion chance it's natural Alexandrite

 

[mina78]

Natural alexandrite is not blue - at least, certainly not in an antique piece. So it's not that.

I am by no means suggesting my stone is alexandrite (in fact I’m certain it isn’t), but I believe antique Ural alexandrite can be the same blue-green as my stone.

Again, my comment was intended as a lighthearted comment, and not a serious claim.

 

[CaseyLouLou]

I am by no means suggesting my stone is alexandrite (in fact I’m certain it isn’t), but I believe antique Ural alexandrite can be the same blue-green as my stone.

Again, my comment was intended as a lighthearted comment, and not a serious claim.

That would be so awesome. I found this one and the inclusions look stringy like in your stone.

3 Ct. Natural and Certified Pear-Shaped Russian Alexandrite — RAF - Rare | Antique | Fine Jewels : Jewels for Generations

An extremely rare and impressive three-carat (plus) genuine, natural, and certified Russian Alexandrite from the Ural Mountains. The pear-shaped brilliant-cut alexandrite displays an 80% to 90% degree of color-change with an Excellent to Very Good quality color-change from Blue-Green to Grayish-Purp

www.rafjewels.com

 

[mina78]

Natural alexandrite is not blue - at least, certainly not in an antique piece. So it's not that.

I’ve just found this chart which is quite informative for anyone interested in the different deposits of Alexandrite and their respective colour shifts.

 

[LemonMoonLex]

Awesome chart on Alexandrites! Saved it! & what an absolutely stunning piece.

I'm giddy to find out what it is but I'm not sure how anyone can think that the center stone is synthetic??! It looks as natural as natural stone gets. It would knock me off my horse if it wasn't!


Hoping it's an alex!!! Even a sapphire would be a treat!

I'm here if you ever wanna sell the piece for the same price lol hehehe

Gorgeous piece!!

 

[mina78]

Unfortunately I've yet to hear back from the lab technician so I'm currently driving myself into a frenzy imagining that it might actually be alexandrite- this is my 1 in a billion pipe dream theory:

The only possibility for this stone being alexandrite is if it's Indian in origin, as this stone displays the same colour change exhibited only by ceylon alexandrite. All other natural deposits display a distinctly different colour change that is either greener in natural light or redder in incandescent lighting.

see below an example of lab certified ceylon alexandrite that mimics very closely the colour change seen in my stone which is teal green to lavender purple:

 

[Cerulean]

Fun thread. Whether it’s synthetic or not, sapphire, spinel or even the A word…

It’s a lovely piece no matter what! But curious to find out!

 

[GliderPoss]

Keep us posted - absolutely waiting with baited breath!

 

[mina78]

Keep us posted - absolutely waiting with baited breath!

Will do! Unfortunately Stephen hasn’t been back in touch yet but he did say he had a 2-3 week backlog so I suspect he’ll be in touch next week some time.

 

[mina78]

I heard back from The Gem & Pearl Lab this morning and have created a new thread with the result of the lab report.