Featured Blacklight Fun

Hi all,
Was surprised today when using the blacklight, the cameo I've had for a long time, had no idea it would glow Looks pretty cool in green
The other 2 brooches are broken, a shame as the butterfly one is nice.

 

The cameo does look cool in lime green. You know it's Psyche. Is she plastic or glass? Very nice, even if artificial.

 

I've had her since 2017, just found my original post with her in it, you helped me with it then custard glass I guess
https://www.antiquers.com/threads/jewel-lot-several-pieces-i-need-help-with.22171/#post-298589

 

Well, I just got a surprise after realizing I had never looked at my cameos in man made materials under my little UV flashlight. The surprise was not that something glowed, it was that something didn't, that it didn't even look purple. Maybe I should wait to do the Big Reveal until I can get photos in daylight. Meanwhile, y'all can guess if you like as to what material looks pretty much the same in both UV & ambient light.

 

Wood ??? Heeehehe!!!!!!!!

 

Right track in a very broad way.

 

When I played the UV flashlight over a little drawer stuffed with cameos in glass, plastic & ceramic, all the items reflected back the purple light with the exception of one piece, which looked just the same as it does in ordinary light.

I purchased the piece when I was still fairly new to cameos because I thought it seemed better quality, that it might be what it appeared to be & not an imitation. The one shop clerk who was always nasty to me was quite certain the cameo was artificial, not unreasonable since the setting is brass. For the price I decided to buy it and remained in doubt about its true nature, finally dismissing hope & consigning it to resin. Until last night. I don't think I ever examined it under magnification before either. This is what I saw:



The cameo is less yellow & the streaks are less evident under ordinary lighting conditions, where it looks more uniformly creamy in color. I had little acquaintance with ivory when I bought it, nor did I know to look for a signature, so did not spot the initials.

It has a trombone clasp & the back is covered over, almost like a picture frame.



If the back were exposed it would have been easier to make the identification. Someone else decided to test for plastic with the hot needle test & must have decided the result was positive or I don't think the brooch would have ended up in a basket of costume jewellery.



I knew what I was seeing last night because I had seen it before with other ivory pieces when examined under UV among items in a wide variety of materials; ivory, both elephant & walrus, just seems to soak up the UV rays, maybe looking slightly yellowed. And we see that a hot needle used on ivory can give a misleading result.

Could've put this under Finds, if finding something in your own house counts. Definitely had some fun with the UV. Thanks, @cxgirl for prompting me to try the experiment.

 

...& a pox to the idiot with the hot needle!!

 

you are very welcome Bronwen
I could be wrong, but I don't think a hot pin would put a hole in ivory, so maybe the hole is natural to the piece?

 

Interesting! This prompted me to use my black light on a cameo of mine that you may remember, Isabella of Portugal. These were my results. To the naked eye, under black light the cameo appears fairly white with a purpleish hue. Also to the naked eye, the cameo in natural light appears more ivory colored than the photos may show. What does this mean? My cameo is also set in brass, the back looks very like yours except for not having the plate that covers the back of the cameo. I have been assuming that it is plastic/celluloid.

 

In the handful of ivory pieces I have, I've not seen a little black pin hole like this, which of course is far from proof that such things do not occur. I think a needle that was hot enough could burn a little pit like this. It's very round & unnatural looking.

The circumstantial evidence is that this is a piece that is hard to figure out. I had written it off as resin after hoping it was ivory, so I have no trouble imagining someone else equally perplexed who fired up a needle. Also, there's the question of whether the carver would have chosen a piece of material with such a blemish?

That's my case, but all questions are fair. It's there now, one way or the other. I'm just tickled to be able to move the cameo out of man made exile.

 

@Bronwen
Also, the initials on mine, though different letters than yours, look carved in the same manner.

 

It means it is ivory. I remember how we agonized over this one. Why did we decide it was artificial? My view has completely flipped. It also has initials on it, doesn't it?

The clasp & hinge on yours certainly are like the ones on mine. The construction of the hinge is unusual, so really have to wonder if they are both from the same source.

 

Found this but to my eye, it's not very helpful:


"Samples of ivory, bone and ivory substitutes under longwave ultraviolet light(365nm). From left to right: mammoth ivory, bone, tagua nut (vegetable ivory), and celluloid."

 

@bluumz Is your piece also heavier than you would expect?

 

What's helpful is the way Celluloid looks by comparison to the other samples.

Edit: Their Celluloid item looks very dark under the UV, but I have a couple in my display cabinet that absorb the light the same way ivory does. On my tagua nut items, the outer layer reflects the purple back, places that are cut down deeper stay quite white. Antler also is absorptive to a degree.

What I have noticed in general is that natural materials absorb the UV more than artificial ones. Celluloid may seem like an exception, but it is based on cellulose.

 

The problem is that it all looks pretty much the same to me. The distance the light is from the piece could account for the changes in light intensity on each item.
Hard to tell about the weight... I guess I'd have to say that the weight is light and correct for plastic... but I’ve always been intrigued by the rather choppy beveled edge on the back.

 

Here is a comparison between a known ivory piece, the moon face, and the Isabella cameo. The Isabella cameo is certainly more reflective, however it has a polished surface when the moon face does not.
I’m still somewhat confused.

 

Finally got a half-way decent photo of a place where I see some suspicious lines in the cameo material. What think ye all?



Compare it to this from RubyLane's RealOrRepro:


"Regularly repeated artificial grain in celluloid."

I'm back to thinking celluloid for my Isabella.