Some of the very old 16th - 17th c. 7-layer chevrons have such a very, very thin innermost layer of green (or other color) glass that constitutes it's innermost (first) layer......now, going on that logic....

We found that there is an innermost very thin whitish layer when peering into the perforation of the 1920s red 5L chevron cane we have here. Does this mean (smiling!) that this is actually red 6L chevron cane?

Hi Joyce,

I have posted many times that LOTS of rosetta beads have contamination in their base layers, that was unintentional, and does not count as a complete intentional layer. Nevertheless, there are also occasional variations upon standard types or styles. When this happens, the base layer is often or usually thick and obvious. When in doubt, I propose the unexpected base layer is a mistake.

The base layers of typical 7-layer chevron or star beads, while proportionally thin and small are nevertheless star-shaped. That is pretty intentional.

Jamey

Contamination: not likely. Intentional: plausible. Accidental: likely. It is still a specimen with an additional layer of color.

Hi David,

Your close-up reveals that the innermost color is blue. Following your line of thought, since the innermost color is blue, followed by white (followed by the actual base layer), this would have to be a SEVEN-layer bead. However, I would classify this as a 5-layer bead with contamination in the base layer around the perforation channel. If someone else wants to count the layers differently, he/she is welcome to. My opinion is just my opinion.

"Accidental" and "contamination" are the same thing. If "accidental" is likely, it is likely due to an "unintended contamination."

Jamey

"Unintended contamination", I feel is a poor choice of words. I would only use that term if the glass was introduced with something that was not formulated into the glass, such as stones from a degrading tank, etc... What I see is a layer of glass that was mistakenly gathered and has inadvertently created an additional color layer. No matter how much we go back and forth playing with semantics it does not change the fact that it exists.

Hi David,

I don't see why "unintended contamination" is difficult or in any way unacceptable. The contamination is not intended. It's accidental. It may just be sloppy.

"Unintended contamination OF THE GLASS—that is, the batch of prepared glass in a crucible—is a very different issue. It's always possible that this glass has unwanted things in in. Devitrified elements, unexpected things (rocks? ashes, whatever). But in cane-making, one way that contamination happens when there is already some glass on the iron, that becomes incorporated into the present gather, and winds up as a coating or partial coating to the central bubble (that will become the perforation channel of the cane). Because a gather of glass that is composed to become a cane gets elongated considerably, there is a reasonable chance that a SMALL contamination may be maximized in the drawing process, and will become either a false layer or something like an "internal stripe" or "partial layer" inside that cane. However, some portion of the time, it will contaminate only a part of the cane channel, and not its entire length. Consequently, some beads from this cane will be "normal" (not contaminated), and some will have unexpected internal features. Sometimes, this internal contamination from a previous gather is itself multi-layered, and results in false layers or partial layers that are multi-colored, and may not appear to be unintentional—although they would be. (This is because we tend to see "structure" as "intended.")

Of course, there are also other things that might happen (in the construction of a cane) that would make the interiors of canes become non-regular, and result from unintended circumstances. (I hope we can presume that no one sets our to screw-up the process, and that these things are accidental.) However, how would one "mistakenly gather" a mass of glass that becomes the center of this cane we are discussing? In other words, how are you conceiving this? How to explain how it gets in-between what becomes ostensibly two layers of blue glass (since the bead in question has an apparent blue base layer, followed by a thin jangled white "layer,", followed by (what I regard as the basic) blue layer?

Of course this feature, and therefore this issue, exists. It is because these things happen that there is a theory to discuss, and that a theoretical glass technician (in this case, me) has to work backwards from the fact, and conceptualize what may have happened to create the circumstance that is the point of interest.

I have documented cane mistakes over the past twenty-seven years. Unfortunately, I have have no practical experience in cane-making. I just understand the process. It would be helpful to hear from someone who has made canes—particularly complex canes, such as for rosetta beads. But I don't know of anyone who has had the experiences that yield results parallel the features of beads we are discussing.

But, like I said, you can count the layers anyway you like. However I may not necessarily agree.

Jamey

Hi Joyce,

The second layer of Luigi's beads, an opaque red layer, is sometimes variegated, having a slightly darker tone in the star on its interior or exterior. I have not seen this in beads from the 1920s. Do you see this shading of the red?

Frankly, I don't recall the tone of the "black" (or blue) layers of the beads Luigi made in the mid-90s. I will try to pull mine out and take a look.

One would have to suspect that a flat black color might indicate new Chinese beads. Did you exclude that possibility?

Jamey

Thanks Jamey,

There is slight variegation in the innermost red layer. Did Luigi use what appears to be opaque black for his dark layers?

If Chinese, they have come a very long way with their opaque red in the past 6 months.

Perhaps not in your experience Jamey, but glassmakers have indeed melted opaque black,and it's not just saturated violet. the Italian nero (black) uses manganese, (violet) chrome (green) and nickel (color varies dependent on percentage from amber through a type of violet) the combination of these three metals can render a quite black glass.I have melted it and worked with it at Nourot Glass many years ago. The biggest issue presented when doing so is that the percentage of colorants gets so high it skews the coefficient of expansion of the glass so the glass must be adjusted elswhere in the batch if it's to fit other glasses in the same piece. You might want to obtain a copy of " Coloured Glasses" by Woldemar Weyl. I may have misspelled his name. My copy is at the other studio. This book is considered the bible of glass colors and has been out of print for some decades. It was published in England in the fifties I believe. Glass melting and colorants have been a well studied science for centuries and in the twentieth century much of the science of same was compiled and brought to a high state of refined knowledge. The industrial glass melters have their own education, science, and information exchange community which contains mountains of glass esoterica. And this community is completely outside the art glass community. The Weyl book comes out of industry.
best of luck in your quest for true glass knowledge,

Art

Dear Art,

I am interested in real knowledge and information--and not just having my ideas rubber-stamped—even by someone as knowledgeable as you.

First of all, my statement was made in the context of Venetian rosetta beads. Among Venetian rosetta beads, in any instance where a glass appears to be "black," it is generally either very dark violet or blue. There is an exception. I have written (many times) about a series of black 7-layer chevron beads from the first wave, that have a black exterior that is a NEUTRAL translucent gray color, appearing black when thick enough.

In order for a material to be truly "black," it must be opaque in even thin sections. For instance, the material jet, from the Whitby mines in England is BLACK. Glass, in thin sections, is seldom opaque. And most conventional "black" glasses are either saturated blue or violet TRANSLUCENT glasses (particularly in a Venetian context), made with cobalt and manganese (but possibly other colorants as well or in-addition to). "Black" Venetian glass (as found in conventional rosetta beads) in thin sections, is usually blue or violet (99% of the time), or neutral gray (1% of the time). If a glass can be demonstrated to have a color (such as blue or violet), and if a glass can be demonstrated to be translucent (even if a neutral gray), it is—BY DEFINITION—NOT "black."

This was the basis of my statement. If you change the context, OF COURSE the veracity of the statement may become meaningless, and provide an opportunity for argument. However, before entering into an aggressive disagreement, a different ploy is to ASK for clarification. I am always happy to clarity—particularly if there is any question of my having been vague or unclear.

It was not my intent to say that true-black glass has never been made by anyone, anywhere, at any time! I try to limit my discussion to the context of BEADS, and to be pragmatic and practical. And in the context of Venetian beads, one can be even more focused and limited (because Venetian beadmakers have a limited and well-known technology and art oeuvre).

Thanks for the reference to Weyl. I will put it on my list of must-read resources.

I will look forward to seeing a truly-black glass that remains opaque in thin sections. If, however, it happens to be translucent gray (like the Venetian glass I have described above and many times before), I would have to exclude it from being "truly black." Convince me.

I am rather conversant with the history of glass coloring—though I hasten to add I don't know everything, and particularly not what has been learned in the mid to late 20th century. I have learned a lot from you, in that regard. Nevertheless, in spite of the work pursued for understanding the chemistry of coloring glass (pursued scientifically since the 15th C. in Venice by notable people such as Baroviero—who may have invented the rosetta and chevron beads), and in spite of refinements of mineral colorants and new formulas for new colors, the coloring of glass remains an ART (not a science). You yourself have told me of instances of following formulas with the expectation of a specific result that was NOT achieved. That is not "science." It's art. It may be (and I agree is) "scientifically-informed art."

Thanks for your well-wishes, It is not a static pursuit.

Jamey

You have an interesting way of issuing an absolute all inclusive or exclusive statement and then qualifying it later in an effort to maintain your position of authority. What part of " No such thing. " is less than absolute???
Alibris books online has two copies of the Weyl book for $240 apiece if you'd like one. apparently it was reprinted in 1999. Must have been a very small press run.
best, Art

The part I explained in my reply.

"However, before entering into an aggressive disagreement, a different ploy is to ASK for clarification. I am always happy to clarity—particularly if there is any question of my having been vague or unclear."

It is a very sad thing when people project their own modus operandi onto to someone else, and when they refuse to see that they are the instigators of aggression and animosity.

This is a forum for sharing ideas and opinions—knowledge. These are conversations. This is not an arena where full-blown academic ideas are presented and expounded. To expect a sentence—a single sentence!—to be inclusive of volumes-worth of information is nonsensical. In fact, nonsensical to the degree that taking a single small sentence and making it into a profound monologue is sort of ridiculous. If you had been at this Forum longer, you might understand that these are issues I have raised and discussed a number of times—in much greater detail than found in the single sentence I posted in reply to a simple question. Joyce knows that, even if you do not.

Who made up the rule that every sentence must say everything that someone might expect it to say and mean? If I had to validate everything I say, providing its context and non-context, its degree of precision, inclusiveness, or exclusiveness, anytime I write something..., I would never get to the topic. I especially would not be inclined to expend the effort when I know I have covered this ground many times before at this very site. But, fundamentally, this is a bogus expectation. I know it and you know it.

"...an absolute all inclusive or exclusive statement." Well, you seem to have forgotten that this was said in reply to a specific single question asked by Joyce—that created the context in which I replied. YOU have taken it out of context, for the purpose of being argumentative and punitive.

"...maintaining my position of authority" ? That sounds a lot like YOU, and not like me. You challenged my statement (unfairly, I'd say), I replied and restated my position, and then you complain about that too.

Art, do you understand that, on the Net (the WorldWideWeb), when you post a message in ALL CAPITAL LETTERS, that this is considered to be S H O U T I N G—and is considered to be rather rude? I hope you were not aware of this. I know your online time has been limited.

I have no faith that any sort of dialogue with you is possible, let alone productive.

Regarding Weyl. I pursue most of my research at the libraries of the University of California, Berkeley. I am reasonably certain I can find Weyl, take a look, check it out, xerox it, or whatever I need to do. I've been at this for a very long time now.

Good day. JDA.

Scroll down to my reply, titled ""Re: Black 7-Layer Chevron Beads."

JDA.

The post is on Page 49 here (today), dated April 11, 2006.

The title of the first post, by Tasart, is "7 Layers and 4 layers being observed by a Russian Blue...."

Scroll down to my reply, "Re: Black 7-Layer Chevron Beads," and my follow-ups below it.

JDA.

Scroll down to my reply, titled "'Black' = Dark Blue."

JDA.

I have a PDF file of the long post I left on July 13, 2004, showing most of the "black" chevron beads I had documented at that time (including beads with "black" layers).

The file is much too large to post here, and the BC.N archive doesn't go back to 2004, so I can't point to it.

If anyone would like to read this PDF file, I will be glad to e-mail it to you—though it's a large file, and will take up a lot of room in your Inbox:

jamey4beads@yahoo.com

JDA.

This is your forum sir, what you say goes and when others disagree you put them in their place not infrequently in an inflamitory way. A pity that. I shall now consider myself thoroughly put in my place and slink off into the dark corners of my glass world never to be a bother to your hignness again with the reading of your words , accepting them at face value and responding thereto.
Where I come from ,no such thing means no such thing. In the context of your last remarks I'd say that JDA having courtesy is no such thing.
Absent your tirade I'm having a very fine day thankyou, and I'll continue to do so. I wish you well as well.
Art