You need to have a resale license to get into this show - in other words it is not open to the public. It really is a "must" for Tucson, so I suggest you start early and ask around in order to get a visitor's badge from a seller, or to be listed as a buyer for a friend who has a bead biz.

This venue has a half dozen or so African traders as well as just about anything else you can think of for beads and jewelry making.

Joe Loux had a new bead estate of mainly Venetian beads and I netted a pair of fancy tabs.
At African Bead Man (Alhaji Kaira) I found a stunning strand of fancy baby king beads.

The five sellers at the Ethnographic Room are not to be missed either. In addition, there are a lot of other interesting beads to be found in the rooms and event center at the Grand Luxe.

I bought a huge (25 mm diameter) Islamic era folded bead from Bassem Elias, and a lovely set of Chinese carved, lacquered beads from Jamey Allen, who is representing the Summerfield Collection. The latter are already composed into a necklace with an interesting Bakelite button pendant.

It's worth the 35 minute drive to Green Valley to see Nicole's offerings of old & new Venetians. I picked up a vintage Moretti necklace this year.

African Village also has many beads and other adornments. The venue was a giant mud puddle this year and I didn't shop for long. But I purchased several interesting and beautifully made woven leather collars from Muso Masiri. They feature vintage African-made brass and bronze pieces as accents.

it's great for us who are not able to go to Tucson. you got some real treasures! I especially like the leather necklace, do you know where it's from? Is it new or old? I've not seen these before.

Leo, aka Trade Beads of the West, had his usual immense pile of old and new beads. I purchased a short strand of mostly Venetian and Czech, including a nicely worn 7L chevron at the center. I find the translucency of the "white" layers to be unusual - since I'm not a chevron expert I'd appreciate any comments about this bead.

Hi Rosanna,

To me your bead appears to be a rare teal 7 layer chevron. Compare outer color with one of your standard blue types.

Nice find!

Hi Matt,
Thanks for the input. It's hard to tell but the outer layer seems to be the same as the dark blue seen in regular 7L's, but somewhat more transparent. The main mystery (to me anyway) is the color in 3 of the layers that appears to be a dirty translucent grey - these are the layers that normally are clearly white in other 7Ls. And this color is not the same as the translucent green found in other 7Ls.

The layers, from the center, appear to be:
dark blue / translucent grey /dark blue / translucent grey / brick red / translucent grey / dark blue

Since my green 7L was stolen last year, is it "bead karma" that I now have an even more rare chevron?

I have one of these grayed chevrons, and recollect a comment from somewhere that perhaps the color comes from being worn under indigo-dyed clothing. Indigo fades under sunlight tho, doesn't it?

The appearance of the white layers, having become spotty and grayish-looking, is due to glass decay. This is not so unusual among 16th C. chevron Beads.

I would not say this makes your bead "more rare" than a green 7-layer bead. But, in all likelihood, 7-layer green beads are not as rare as some people would like to believe.

The idea that the exterior color of your bead is or was "teal" is mistaken, of course.

Jamey

I'd never seen this type of white glass decay on a Venetian bead - explains a lot.

And yes there is no way the outer color is teal. At first I thought the outer color was green (in poor artificial light), but in daylight it is clearly the same dark blue as other old 7L chevrons.

I believe that what you see is the white glass being way past its prime in the crucible at the time of manufacture. The white used in these beads is a fluorine opal which degrades over time in the pot. Over time it gets less and less opaque and hard white. Also fluorine opal at temperature is quite caustic to the furnace environment and dissolves the bricks and pots in the furnace. I've seen these beads before and think that all those white flecks are small pot stones in the glass.
just a glass makers opinion

Thanks Art -
Another tidbit of info is that there are a few chevrons in the Picard book that have layers described as white but look like light grey with white flecks, same as my bead but slightly lighter in shade.

I'm still not sure about the outermost layer since it is thin, and not backed up by the usual solid white. So it looks like translucent greenish in strong daylight, but in other light looks just like the inner layer which is more a match for the usual dark blue seen on 7Ls.

Here is a pic taken in sunlight, with 7L blues on each side. To my eye the outer layer is definitely greener than the blue on other chevrons. I have two opinions that this would be called "teal", which I think is the same as the "translucent blue-green" described in the Picard book as a color found in 7Ls.

The color rendition is difficult on this bead. Cameras do not have the same dynamic range as the human eye!

I agree with Jamey, that is the standard smoke blue. It only looks different due to the thinness and that it is not backed up by hard white but the gray down tones it. If you look at the other two sevens you show you will see flecks of white stones in the white.

We have a camera with a greater color range so I'll try to take another photo.

I read that the "natural" color of glass was typically a pale green due to iron oxide in the sand. Manganese dioxide was/is used to "de-colorize" the glass to make it clear, but I don't know if that was widely used in Venetian glass making 500 years ago. Is it possible that the slightly green translucent color in these old beads - as seen in the inner layer on a lot of 7Ls - was due to using "natural" glass that lacked the de-colorizer?

And if the slightly green glass was colored further by adding cobalt oxide to get blue glass, a slightly green tinged blue was the result, rather than the more pure cobalt blue color we all know and love?

Hi Rosanna, Yes, iron is the most common contaminant in glass making materials and it contributes to the gray green you see in the edge of window glass. Coke bottle green is iron, but in a calculated added amount. Manganese makes purple in glass which is chromatically opposite to green so was added in minute amounts to "decolorize". clear glass when going for that crystal look. It is not added to glasses which are made to be colored unless as a colorant itself. Manganese in Clear glass is photochromatic and turns purple with prolonged exposure to ultraviolet light. The old purple bottles you see are this feature at work. About the time of the first world war Manganese became a war material so was abandoned for decolorization and selenium was substituted. It isn't photochromatic so the newer bottles don't change color over time in the sun.
It has long been my opinion that the chevron makers of old used waste glass for the first and third layers in their beads to bulk up the core of the cane with less expensive glass where it wouldn't show in the finished bead. This would explain the wide variety of core colors observed. Keep in mind that these beads were made for export to places that were primitive by European standards and much less care was taken in making them than in making the fabulous glass Venice was famous for in the salons of Europe at the time. Precision in construction, and color was not a prime consideration, production quantity was. Both the cobalt for the blue and the copper compounds for the red and the fluorine compounds for the white were expensive so using the waste green glass at the core of the cane made sense from an economic standpoint. Further in the 1500s the materials used in glass making were not nearly as refined as in modern times. So contaminants in the coloring materials could and did contribute to the color outcome. Cobalt is the strongest colorant in the glass chemistry world. As little as 1/4 of 1 percent will yield good color. Cobalt will swamp other colorants in a batch so the iron contaminant green would have no affect. Other colors require several percent for effect depending on the darkness of color desired. Some colorants produce different colors depending on furnace atmosphere and some yield different colors depending on amount added to the batch. Nickel is one of these. It can produce a glass light amber to amber/purple/ to dark gray. It is usually used in conjunction with other colorants. The dark blue you see in the old chevrons is not pure cobalt blue, it has nickel in it as well, making it what we used to call smoke blue in the glass shop. We added nickel to get that color. You see pure cobalt blue in the modern Chinese chevrons. I believe that the chevron makers of old were not looking for a precise effect in color and/ or pattern as witness the loose pattern construction of in the ancient chevrons and the color variety. The bright green ones were made to be green and the black ones were made to appear to be black (as Jamey has pointed out there is no true black glass) but I think that the blue varieties reflected the materials available at the moment and production necessities for meeting delivery requirements. Add to these considerations that in melting glass in pots the residual glass in a color pot will affect the next glass melted there.
Concurrent to these beads being made in Venice they were producing highly refined glass and objects from it like the goblet shown here. The beads were not their prime product, but production items made in great quantity for export so made with much less attention to perfection. The precise patterns you see in my beads is the result of extreme care in the making of the cane, something not possible in a high output production environment.

I'm very happy to be learning all about the possibilities of my "not exactly typical blue and with dirty white layers" 7L chevron.

Since other similar beads are out there, it looks like the best hypothesis is yours - that poorer quality, contaminated, and/or waste glass was used to make these chevrons, making the colors much less vivid than in the "typical" chevron production.

I appreciate all the responses on this bead - very educational!

Your explanations really help me to understand what I'm looking at.

Thanks Art for all explanations in the making of the coloring materials.
We have in our Museum a few samples of these muddy colors. It is hard to qualify them either as blue or green chevrons.
In the pictures it seems that in the last layer the green has sunk below the blue as if being colors glass of different density. When looking at a bright light the beads look greenish, when looking in the shade they are more bluish.
The overall effect is a kind of muddy blush green. I guess it is why they are described as teal to differentiate them from the regular blue and green ones.
I do agree that the 7 layer chevrons were not a refined product from Venice, cheaply made with no material or precision or artistic requirement. It was one of the ingenious products made and aimed to facilitate trade for the European expansion in the third world of that time.
Looking at all 7 layers, you might suspect that a bunch of them could have been part of training or testing skill for apprentices in the glassware industry.
Because of their numerous variations and their crude appearance they have created an interest and the magic is that today they are revered and coveted by many collectors. They are a genuine and intriguing relic of their time.
JP

The topic of non-typical cobalt-blue glass, of a slightly more-greenish tone, found in some chevron beads was addressed by me in 2006. Screenshot here. JDA.

Hi Rosanna,
i have added an image from 7-layers with the greyish white with flecks.
The one is a bit similar as yours. The other one is with the typically blue outer layer.
Regards Christian

Still to my eyes the blue on your bead is different than the standard blue 7 layers. Would blue/green be a better way to describe? I do understand that thickness of glass, grind and color directly under the outer layer can influence the color we see. I have several of the 7 layer chevron beads with the interesting grey and white flecks. Some of the outer layers are a darker blue/green that may be hard to distinguish from the standard blue color we usually see on these beads.

I am by no stretch an expert and this is my humble opinion.

Thanks,
Matt

Matt & Christian -
Thanks for posting your beads - the color of the outer layers and the white layers on yours are very much like my bead.

The colorant that made glass white in the 15th/16th Cs was tin oxide. Milk glass (lattimo), colored with tin oxide, was devised by Angelo Baroviero—who was (most likely) the inventor of rosetta (chevron) beads; and who devised the Venetian strategy of making molded canes for rosetta work (including millefiori beads). Lattimo was also used by Baroviero to create white vessels that were designed to resemble white Chinese porcelain—that was a fad among Venetians and other Europeans. Angelo was celebrated for his excellent chemical breakthroughs, and the color pallet he devised, that produced glasses of different colors that were compatible with each other—all of which are seen in early chevron beads and millefiori beads.

Note the reference to tin oxide under Colored Inclusions here:

https://en.wikipedia.org/wiki/Glass_coloring_and_color_marking

Fluorine-white glass is a rather more-modern composition.

Unless it is demonstrated to be otherwise, I will continue to understand that some early white glasses (such as those used to make white layers in rosetta beads) decay in the manner seen in the beads being discussed. This having become spotty and grayish. Or, presenting white spots on a more-gray ground. And, I have discussed most of these topics numerous times, here and elsewhere. I'm using the current links to support information I understand from research I began in 1980. At the moment, I don't have time to go through my copious library and cite old sources.

JDA.

This Net essay confirms a considerable amount of information I have gleaned from over thirty-five years of reading archaeological reports, and technical journals related to glass history and chemistry:

https://renvenetian.cmog.org/chapter/material-making-glass-renaissance-venice

JDA.

https://www.britannica.com/art/glassware/Mid-15th-to-mid-19th-century

I defer to Mr Allen’s research on ancient glass. I was led to believe that the Italian recipes I worked with in the 1970s were of ancient extraction. They were what Venini was using at the time. Perhaps one day someone will do spectroscopy on the glasses in ancient chevrons and ancient nueva cadiz, including those from the new world. Then many questions will be definitively answered.

Rosanna,
Thank you for the mini-tour! The Big T is the absolute destination for great beads and great company of other bead people! It appears that the Symposium at the Sonoran Glass School, in it's third year, was a success as well! Hoping to go in 2020, consistent with my "even years" plan. :)