Featured Eyes Have It: Are These Intaglios the Same?

I have mentioned this matter here & there in other threads. Now I need those who will to lend me their eyes & observations, as I have become dizzy & cross-eyed with it.

This engraved amethyst is in the Bibliothèque nationale de France (BnF), Cabinet des Médailles (CdM):



This glass paste intaglio lives with me:



The question is whether the glass version was made from a mold that was taken from the amethyst or from some other engraved gem that was a copy. The glass is slightly concave & details around the edges tend to drop out. Deeply engraved places are captured well; shallower features are sketchy or disappear. On the other hand, the glass has little irregularities not present on the amethyst. They are the same size. Where it is possible to compare like with like, would you say they are the same? If not, where do you spot differences, apart from the obvious difference of the name? All help deeply appreciated.

 

to me, the faces in the side by side photos are different. The amethyst face is more full on whereas the other is more of a profile.
In the side by side photos, what is the one on the right? Not your piece is it?
in the 2nd side by side the arm and hand are different

 

The brownish piece is mine. I should have pointed out that these are very small & detailed. How they look is changeable depending on the lighting & the angle. I have only 3 photos of the amethyst to work with. I don't have the equipment or the skill to get my piece at exactly the same angle to the lens as the BnF photos. I have rotated them to try to make comparison easier, but the alignment is never perfect. The amethyst has some sort of inclusions or discoloration that makes the face hard to see. Here are the 2 other pix of the amethyst:

 

The British Museum has a copy that is extremely close, but I can find discrepancies in it.

 

I don't think they are the same Bronwen .. same subject but different rendition ... Joy.

 

We'll keep track of observations like this & see if they can be verified or refuted. In this case, think the difference may be largely the slight curvature of the glass, so that the head becomes tipped away from the center. The angle of head on neck of the British Museum's gem definitely does not seem to match.

 

I keep going back to the 2nd side by side photos, the instrument (zither?) looks to be different in each view

 

OK, what differences particularly stand out for you? I have been trying to compare, where I can, very small, fine details, such as the strings of the kithara, the crest of the helmet & the belt of the sheath, places I think it would be difficult to replicate exactly.

If you enter 9212-9217 in the box for searching by gem number here:
http://www.beazley.ox.ac.uk/gems/tassie/default.htm
you will see 9212, which is the amethyst, 9213, which is a copy of the gem made by William Brown, 9214 & 9215, which are the same composition with obvious differences, and 9216 & 9217, which are the same scene, but a different composition. The difference most obvious to me in the Brown is the angle at which the kithara is held.

Without being able to put them side by side under a microscope, the only thing I could do beyond examination by eye is to print out the photo & start measuring angles & proportions. Thought I'd throw the problem at you guys first.

 

Kithara; similar to a lyre, but with a sound box at the bottom. The glass has an extra curved line that looks like there was a bubble. Don't know if this view differs by much:

 

How about the face & angle of kithara in this photo?

 

It would have been nice if the BnF had included a photo of an impression taken of the gem; a good one will show details more sharply than photos of the gem itself.

 

I made the ovals pretty much the same size and tried to register them with the instrument. If this gets annoying, I'll remove.

 

As I said, I'm absolutely cross-eyed at this point. You'll have to tell me what to look at. Is there anything not caused by glare & angle?

The dimensions of the amethyst are, according to the CdM: H. 1.6 cm, l. 1.3 cm. I don't have good calipers (or steady hands); I get H. 1.6 cm for mine & a bit more, 1.4-1.5, on the width, but there is some excess material at the edge. Pointing this out so you will appreciate how small the kithara strings are. Both instruments have 7 strings.

 

The lettering lines up. At this size, there's no way to reproduce that so minute so perfectly other than from a mold.

 

As long as I don't spend too long watching. Sort of thing that could cause a seizure in those susceptible! The way it ends up looking to me is like the same image being turned back & forth, between a more frontal, purple view & a brown view that is slightly turned away to the viewer's right. Thanks. I know my photo editor can make transparencies, but I don't really know how to use it well enough to fiddle with it until everything is the same size at the same angle. Every additional photo comparison helps. Just when I think a find a point where the 2 do not match, I find that in a different photo I've taken of the glass, they do.

 

Only one has lettering. And that's the whole point. Admittedly based on photos alone, but Christopher Lightfoot, formerly a curator in the Met's Greek & Roman department & their expert on glass, gave me his opinion that the glass intaglio is Roman, in part because in the Georgian era, when it was mounted in a miniature, fob sized seal, there were still many genuine paste gems on the market, no need to fake them. If the paste copy is Roman & taken from the amethyst, yet has no trace of the name engraved on it, what do we make of this Pamphilos? The gem was a gift to Louis XIV. Signed gems from antiquity were highly coveted. Hmm.

 

If you could layer one image over the other I think you would see more differences.
I don't think what I have marked line up correctly from one to the other.



This matches the amethyst much better than yours does.

 

Not sure what 'this' is that is a better match? I'm burned out, so forgive if it should be obvious.

Not being able to get them both at the same angle to the camera lens is a major problem. I can't overstate how different the paste intaglio can look with just the slightest shift. Originally I did not think it looked much like the amethyst at all. Then, the more I looked, using different lighting & different magnifiers, tilting it this way & that, the more I saw that one detail or another actually is there. For example, the gorgoneion (Medusa head) on the shield, didn't resolve into anything coherent until I had done an awful amount of looking.

Many things are more easily seen in photos than directly. Other than the photo of the complete stone, the photos of mine were all taken with a USB microscope, while details of the amethyst are from one or another of the photos available on the Internet, cropped & enlarged. The CdM description does not say whether the amethyst face is flat or convex. If it were curved, as the glass is, think they would note it, so think that's another source of distortion.

I'm -grudgingly - open to being convinced the paste is not a direct copy of the amethyst, but you will have to come up with a distinct difference that stays consistent. The Brit's copy is really good, but one clear difference is the helmet set aside on the rock behind him, shown here in an impression of the gem, which is why the other 2 pix have been flipped to face the same way: