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Glass Discussion & Research. NO IDENTIFICATION REQUESTS here please. => British & Irish Glass => Topic started by: orangeglass on June 12, 2014, 07:51:43 PM
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Hi all,
For show my new Monart vase, shape SA size VI (8") - I was suprised by the size - somehow I expected it to be smaller and it's much nicer than I expected, the colours are really stunning!
Blue green colour-way with lots of Mica flakes - mainly silver but also contains gold flakes - not aventurine - similar to colour code 342 or 504? Does anyone (Gary :D) know the correct code?
As usual it has a bit of a crack in the base - my 4 favourite Monart pieces are ALL cracked!
Looked particularly lovely in today's sunshine ;D
Roberta
Roberta
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Where the flakes look gold, are they exposed to the air?
Silver will tarnish, and glass with silver applied to the surface will end up with the silver tarnished.
But I thought that what was used was mica flakes, (Woolworth's christmas glitter), that shouldn't tarnish, but can go a bit yellowy, with age I think.
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All I can say it is either 342 or 504, I have not seen (to date) a labeled piece with either colour code, to make a positive identification.
The gold flakes are silver mica that have discoloured.
The silver mica does look good in the sun light.
Gary
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No. they are not exposed - My first thought was maybe the silver had just gone a funny colour!!
There seems to be mainly silver in quite big flakes of varying sizes, but definitely gold in there but just smaller flakes - the picture doesn't show it as it is in reality - the camera shows more gold .
The are two colour codes on ysartglass - the first just says (342) green / blue & mica whereas the second (504) says blue / green & silver mica - so whether this is just differentiating between more green or more blue colour or any difference in the mica I'm not sure.
Maybe they just used two different mica batches - one of which had been lying around and got tarnished before being used in the glass ???
Roberta
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Mica doesn't tarnish. I think looking at the photos, coloured frit has been used over the blue because there are slightly brownish patches and not just over the mica and that's what's making the mica look gold.
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Mica can be yellowy. (image in link below)
http://fi.wikipedia.org/wiki/Tiedosto:Mineral_Mica_moscovita_GDFL107.jpg
I am positive I can remember playing with flaky sheets of the stuff in chemistry classes at school.
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The materail used by the Ysart's to produce the silver effect was indeed bought from the local Woolworth store. It's original purpose was for Christmas decoration (packet shown below) and as such I don't believe it is silver mica in the true sense.
Gary
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I think Gary is correct in that the Woolworth's mica isn't actually really Mica.
The gold flakes are just that - there are individual flakes (gold) some of which are overlapping, next to and on top of the silver ones, they are just smaller in size.
Gary - have you got a bowl in this colourway? if so does yours have any gold in it?
Roberta
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Just found the magnifying eyepiece thingy - I think Gary was right - it is the silver that has tarnished - looking at some of the bigger flakes they are both silver and gold, some flakes are all silver, others all gold.
There are quite a lot of bubbles in the glass so whether that has something to do with some parts of the 'mica' oxidising or something, or a reaction when it was made who knows. The 'mica' looks just like torn up pieces of silver foil.
Roberta
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Mica is a heat-resistant chemical compound, containing silicates which is naturally flaky and shiny.
It contains neither silver or gold metals.
http://en.wikipedia.org/wiki/Mica
Real mica is what the woollies christmas glitter was.
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Okay, we stand corrected :D
Why couldn't they get it from other sources then - only Woolies at Christmas!
If it is a naturally occurring mineral there will be variances - I believe it looks more translucent glittery until it is put into the glass when it appears more silver (or gold!) ;D
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The world was a much "smaller place" then.
Fancy goods were not readily available.
For heavens sake, even I can remember when we made our clothes, buying material and patterns from Simplicity and Vogue - because we couldn't buy clothes in the shops.
Mica glitter from woolies was a luxury!
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I just meant that as "industrial' as well as 'art glass' manufacturers they had suppliers for the coloured enamels, and the gold (and possibly other colours) aventurine (expensive), you would have thought they could have got hold of Mica flakes from another source!
Roberta
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Speculating here, but perhaps is simply wasn't common to be using mica chips in glass?
Monart used it and so did the unknown Romanian maker of the "Monart-a-likes" during the same period - but I don't know of anybody else who did.
The Ysarts were innovators, inventors, researchers in what they could do with glass - pioneers of hand-made individual works of art!
And they only used the mica during the winter - they didn't buy up loads to use during the spring, summer or autumn.
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I have 3 pieces of Monart with silver inclusion ( 1 boxed so can't compare), the images below are taken with a macro lens. The first two are from a vase with a fair bit of discolouration in the silver inclusion. When viewed from different angles it is not so pronounced. The third image is of a vase with very little discolouration no matter what angled it is viewed at (hope that makes sense).
What information have you got Sue that the Christmas glitter is real mica, I have no idea what the Christmas glitter is made of.
Gary
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The first two pictures are exactly what mine look like, but I couldn't manage to take a picture of mine and get it it look like reality!
I have seen a piece where it looks like your last picture - definitely silver!
Roberta
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To be honest, I have no evidence that woolies mica was actually mica - but what else could it be? It's always been referred to as the mica flakes used by Woolies for christmas glitter.
Does it say anything in the book about it?
The pack does insist it's heat resistant. ;)
Silver is a very difficult metal to incorporate with glass. Tiny bits like that would melt and react with the glass to produce ochrey yellow colours.
If silver was in it, I cannot imagine that none of the silver would have reacted in any piece, so silver metal is completely ruled out.
Woolies wouldn't have been selling real silver flakes for glitter either - they'd tarnish so quickly they'd be useless, and real gold ould have been a tad expensive.
I can remember an oven door having a window made of mica in a lab.
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I bow to your superior knowledge of chemistry Sue, that it is not silver.
I agree it always been referred to as silver mica myself included, though this is based on hearsay only.
What got me thinking about the subject of Christmas glitter, was when Lustrousstone mentioned that mica does not tarnish, where it does look tarnished in Roberta's vase and the first two images in my last post. Hence the possibility of it not being real silver mica.
Gary
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If you look at the images of mica mineral in the links I posted, you'll see how is can be both yellowy (gold) and silvery (clear). It's naturally flaky and in "sheets".
But it's decidedly not doing all the silver/glass reactions in Monart that the silver chloride crystals used in Mdina glass do. :) (It converts to being silver metal ions and chloride ions in the heat).
I suspect that when the term silver mica is used, it really should be silver-coloured mica - but that the word coloured got dropped. It is merely referring to the colour achieved, not the actual metal being used.
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I think it is a bit like the variances in aventurine (even though that is not a naturally occurring thing - the ones used for glass) in that you get slightly different colours, shades in it - that is why I was initially questioning the colour number refs. on ysartglass in that one states silver mica and the other just mica.
I do think it is real mica used because of its heat resistant properties, as has been already said - other metals etc. would react to change colour.
Roberta
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:)
Mica can be made up from several diffferent formulas - there's a description of the different metals that can be incorporated at different points on the molecule in the first link I posted - but none of the metals are silver or gold.
I imagine different chemical compositions of mica might have different colours/light reflecting/refracting properties.
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Plenty of Mica used in Bohemian and Czech glass, here is one item stuffed with it (to great effect):
http://www.glassmessages.com/index.php/topic,51869.0.html
John
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:)
Doh, I'd forgotten all about that jug, thanks for keeping me straight, John. ;)
So in Eastern Europe, in the early part of the 20th century, behind the Iron Curtain, mica was used rather more extensively than it was in the rest of Europe.
But the Ysarts were quite possibly the only ones using it on the western side of the Iron Curtain?
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I doubt it somehow, just on general principle really. ;D As soon as we make an assumption an example crops up that contradicts.
No doubt many Victorian glass makers used mica and it would have been no secret in the 20th century. Sowerby for one, two posy vases: http://www.flickr.com/photos/art-of-glass/6029998615/in/set-72157627404389474/
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I thought that was an image of two elephant's behinds!
Shows what I know about old stuff then doesn't it? ::)
Zilch! :-[
I honestly thought the use of mica was something highly unusual to the point of being scarce. I certainly haven't seen much on my travels.
It's how I got taken in by the unknown Romanian stuff that isn't Monart. I saw mica, and that was enough!
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Can nobody see what I see on Roberta's vase?
I think looking at the photos, coloured frit has been used over the blue because there are slightly brownish patches and not just over the mica and that's what's making the mica look gold.
Mica from a batch from a given supplier will have the same composition because it will have come from the same mine/quarry though the possibility of impurities can't be ruled out.
Mica is quite easy to tell from silver or other metal foil because it has pieces with straight edges and often square shapes. There are wide spaces between pieces. There are no crack shapes between pieces. The pieces appear "relatively" large, i.e., not powder, and are not formed from much larger squares or other shapes that have broken up, though several may clump together in "blobs". The pieces in the Sowerby vases are large flakes, not the "Christmas glitter" size commonly seen. If they were foil they would have "cracked"; see my Mike Hunter paperweight linked below.
Mica is very common in Bohemian Victorian glass
Here is is only in the transparent stripes http://lustrousstone.co.uk/cpg/displayimage.php?pid=1570
Here is all over but under amber glass
http://lustrousstone.co.uk/cpg/displayimage.php?pid=1526
It is possible to use "silver" metal foil inside glass. It is seen sometimes in Murano glass as here http://www.ebay.co.uk/itm/Murano-Glass-1950-039-s-Silver-Leaf-Murrine-Canes-Bowl-/360884865699 and Mike Hunter has used it here along with gold foil http://lustrousstone.co.uk/cpg/displayimage.php?pid=443
I do not know if it is silver or another metal.
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The brownish patches aren't that - it's just the camera / lighting altering the way the coloured enamels look.
It's exactly like Gary's first & second pictures.
just a thought to throw in to the mix - we all know the story of Mica being bought at Woolies and only when it was available at Christmas, but do you think this is one of those times when the story has a degree of accuracy but then becomes "the only story"?
Is it possible that the Ysarts or even Isobel Moncrieff first bought it at Woolies just to try out? And when they decided it worked in the glass and wanted to carry on using it they could have found another supplier for it at some time? Which would then mean it would have come from different places and had a different composition therefore the differing colours?
I know in my previous work as a designer this is often what would happen - you pick things up often locally, experiment with them - if you use them in production you find a supplier.
just a thought anyway ;D
Roberta
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Using silver foil is an incredibly difficult thing to do, because of its proclivity to react with the glass.
William Walker and Michael Harris developed a method together for Azurene in 1978, which won a Design Council award in '79. It has been disseminated and in use since then. Allistair Malcolm is another contemporary artist who uses it to incredible effect.
I would imagine its use in Murano would have been one of the "ancient secrets".
I have no idea if the methods are the same or not.
I do know Mike Hunter has said; "There is no correct way of doing anything - you just do what works."
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Your third picture quite clearly shows coloured enamel (it looks brownish in the photo) over the mica - some of the mica bits are actually part silvery and part "brownish".
I doubt Monart glass used enough volume of mica to make it work going anywhere other than Woolies for a few packets. A little goes a very long way.
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quote from Sue ....... "There is no correct way of doing anything - you just do what works." .... I think that's one of the best truisms I've heard in a long time. ;D
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From Mike Hunter - masterglassmaker - (who uses a bone handled table knife as a glassmaking tool) not from me!
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I think it's a great piece of philosophy, from whomsoever it came ;D
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possibly of interest in the context of this thread, are comments in the glossary of Leslie Jackson's book 'Whitefriars Glass'.
Under the heading of gold foil she says.............
"Initially gold foil was used in the main body as well as in the stems and knops. (pl. 35ii) Later the technique was largely confined to the stems and knops of goblets, continuing until the 1930's. (pl. 76) Platinum foil and mica scales were used in a similar wa, but are much less common."
The word leaf is not used - implying that it wasn't real gold that was being referred to. :-\
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I think it's just terminology foil = leaf