Featured Cameo Brooch

What is this made of? Hard and cold to touch but can’t tell for sure what’s exactly the material.

 

Marble. It's late 19th C.

 

Is the color right for marble?

 

'Lava'.

 

Whichever, get that tick off her forehead before she gets Lyme!

 

I'm with Bronwen, lava.

 

Thanks. Is the image of a known person a fantasy one?

 

Same here. Lava and in really good shape. They're easily damaged.

 

They also require great care when attempting to clean. Highly porous & often dyed to even out or improve color, they easily stain, fade or discolor. Like other calcium carbonate based materials, they can dissolve in any kind of acid.

 

She is dressed like a sibyl, but like Giovanna Di Rosa, who had this one, I haven't been able to pin her down. Figures who look like this sometimes turn out to be allegorical, such as the Personification of Astronomy; some female saints, & even the Madonna, have been depicted in this sort of garb. This one is either Music or St. Cecilia, depending on which painting you think is behind it:

 

Not seeing the porousity I'd expect from lava, and it looks too pale, but that may be the photo.

 

Geologically speaking you are right, obb. What is commonly called lavastone in jewellery is in fact volcanic breccia, formed by lava, and tuff, volcanic ash consolidated into stone. There are different kinds of tuff.
So technically/geologically speaking it is tuff or breccia, in jewellery terms it is lava, which volcanic breccia is (with other volcanic rocks added to the lava).
As you know many jewellery terms are invented just to confuse us. This is just one of those cases.

Tuff can also be quite porous. I guess it depends on the level of compression, but I leave that to the geologists among us.
In case anyone is wondering, tuff is not tufa. It is what Italians call tufo, one letter difference.

 

The color is a pretty common one. Between naturally occurring colors & dyes (I have seen newer pieces in pink & green), there is a range from white to black, with various earth tones between. This gang belong to me, so I have been able to examine them directly & confirm the material:


This parure, alas, is not mine:

I'm not a geologist, but I play one on the Internet. No, really, there is much more I would like to know about 'lava' cameos. There is not much to find written about their making.

I even bought a little book on volcanoes to try for a better understanding. One thing I knew from handling a number of them is that some are coarser/grainier while others can be quite smooth. This can be explained by the distance from the source at which the material was collected. Ash is carried from the eruption on the wind, with larger, heavier particles dropping to the ground sooner.

A cautionary tale about what can happen with bad handling:



It is also instructive about the surface vs. the underlying material:

 

Since I want to make sure I have it right on the web site, checked into this. Quick Googling seems to indicate that 'tufo' is a word only in Spanish, & that one meaning is the noxious gas given off by incomplete fermentation. Suspect volcanic fumes smell this way too. But if you want to find out about the volcanic material, you have to search for tuff or tufa.

Think there is a confounding factor when it comes to Vesuvian lava. Naples & all southern Italy sits on a massive limestone shield. So when Vesuvius has a pyroclastic event, wouldn't be too surprising if a lot of what gets blasted out & is light enough to be carried on the wind is calcareous. Have been told these cameos are limestone because they bubble when a bit of acid is dropped on them. Well, they are, just pulverized & compressed again into an amorphous mass instead of the layers of limestone sediment.

'Lava' is a non-specific term for anything solid that comes out of a volcano.

 

Thanks for all the great info.
Any agreement on the age?

 

Hard to say with certainty, although hinge precludes its being super old. Think OBB's estimate is as close as any. Quality of both carving & mount is better than one tends to see once the 20th century was well underway.

 

She's also a bit chubby by modern standards, so odds are this is Victorian.

 

Somewhere there is, or was, an art work in another medium that this is based on. She doesn't come up with images of well known sibyls, so suspect she is an allegorical figure & could be any branch of knowledge, which makes it difficult to search for her. Classical & neoclassical cameo subjects got replaced with more contemporary images when the Victorian era ended.

 

One of those google translate things, I guess. They also love to mislead you into uttering obscenities in a foreign language. Don't trust them.

The Spanish word tufo means a bad smell, but it has nothing to do with the Italian word tufo.
I looked up the Italian Wiki page on tufo:
https://it.wikipedia.org/wiki/Tufo
And this is what wiki calls tufo nero, which looks like dark grey breccia, and has the same colour as some lava cameos:


Not that wikipedia is always correct of course, but I trust Italians to know their own language.
In Italian sources I only found the word tufa as a verb in the old Italian dialect of Romanesco, where it means to regret or lament something.

In your link it says:
"Tufa, which is calcareous, should not be confused with tuff, a porous volcanic rock with a similar etymology that is sometimes also called "tufa"."

But I agree, volcanoes are rather careless in what they spew out. Or where they do it, for that matter.

Transposing a word from one language to another often leads to very confusing definitions, as you noticed with Italian and Spanish. The word tuff means spit (saliva) in the dialect of my region.

 

The cameo world seems to be plagued with confusion, inaccuracies & inconsistencies when it comes to the names of materials commonly used. That's what I meant about Vesuvian lava, the material blasted out may be powdered tuff. Most 'lava' cameos are definitely calcareous, so what to call them? Then there are ones made using calcareous water from a hot spring & a mold.

I find Google the best at the job, but the way they tailor search results to where you are located & what they think you want/need based on past searches drives me nuts. I have sometimes asked friends in other parts of the world to run a search for me, & often enough they have come up with something useful that was not shown to me, or not high up with what are supposed to be results that most closely match what you asked for. Think I got an entire page with no results for 'tufo' other than definitions of the Spanish word, mixed in with entries for tufa, tuff, etc.

I find IM Translator very helpful, but because what I so frequently read & correspond about is such an obscure topic, it comes up with highly amusing interpretations at times. There is a German firm that puts things, including cameos, up for sale on eBay & clearly uses a translation program for their descriptions but has no one with adequate English who looks them over to see if they quite make sense. In spots you have to translate the translation. This is from the description of an historical figure: with a new beginning in the State were so quite figuratively also the old braids.