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Glass Mall => Glass Market Place => Topic started by: marie anne on December 13, 2010, 10:52:33 AM

Title: Sklo Neodymium Paperweight on eBay
Post by: marie anne on December 13, 2010, 10:52:33 AM
Hi,
I've a paperweight which I think is a Neodymium weight designed by Vladimir Jelinek follwing the Glass Messages thread
http://www.glassmessages.com/index.php?topic=5641.0 (http://www.glassmessages.com/index.php?topic=5641.0)
see photo below.

It's up for auction on eBay
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=170577538131&ssPageName=STRK:MESE:IT (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=170577538131&ssPageName=STRK:MESE:IT)
and is item number 170577538131

Thanks for looking,
Marie.

Title: Re: Sklo Neodymium Paperweight on eBay
Post by: Lustrousstone on December 13, 2010, 12:23:09 PM
It's NOT Sklo Union (those factories really only made pressed glass). It is probably Zeleny Brod Sklo. (None of your photos actually show the colour under daylight or an incandescent (old-fashioned, non-energy saving) bulb. It should be lilac, which may lose you sales)
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on December 13, 2010, 12:49:51 PM
Hi,
I've pulled the listing on eBay while I get a bit clearer on this.  I'm more worried about not describing correctly than losing a few sales.  I didn't say 'Sklo Union' in the listing I said 'Sklo' based on the Glassexport label.  I'll try and get some daylight photos but the light hasn't been great lately.  We only have the energy bulbs in our house now, but my photos are taken with bulbs which are supposed to reproduced the colour balance of daylight (to my limited photography understanding). 
The paperweight I was comparing mine has the following link     http://i5.photobucket.com/albums/y195/glassie/misc578.jpg (http://i5.photobucket.com/albums/y195/glassie/misc578.jpg) in the glass message thread.  If I understand the thread correctly then Marcus is saying that he has a similar one by Chribska. 
Thanks for your reply.   I'm always open to comments.
Marie.
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: Lustrousstone on December 13, 2010, 01:34:23 PM
Sklo is just the Czech word for glass. From unravelling the thread, your label was used on glass exported by most of the Czech factories (not just the Sklo Union ones) and Marcus is saying the paperweights are probably Zeleznobrodske Sklo and possibly designed by Jelinek.

Daylight bulbs are still halogen bulbs; they are just colour balanced to create the effect of daylight but still produce the wavelength that turns neodymium blue. Take your photos in front of a window on white paper and you should have enough light even on a grey day (turn off the flash)
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on December 13, 2010, 08:24:16 PM
I've taken a new photo in light from the window - shown on the left and compared with a photo lit using a 'daylight' bulb on the right.  There isn't a huge colour change to my eyes.  The one on the left has a muddier tinge to it but that's about all I can see.  And thanks for unravelling the thread.  I still like the paperweight as a nice piece of art glass but am now less convinced it's neodymium. 
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: Lustrousstone on December 13, 2010, 10:06:34 PM
What colour is it when you take it outside?
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on December 15, 2010, 08:38:26 AM
Sorry for slow reply.  I was helping my mother move house yesterday.
The central coloured region goes a soft pink when taken outside!  The colour is best in the region below the big bubbles.  I will try to photograph it outside but I haven't the time to do it today as I'm off out to do more unpacking shortly.  I will upload a photo in the next day or two.  I'm not sure if my camera will capture the colour properly but I'll have a go.
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: Lustrousstone on December 15, 2010, 02:31:05 PM
If it turns pink, then it's neodymium,
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: flying free on December 15, 2010, 03:39:49 PM
'The central coloured region goes a soft pink when taken outside! '

having looked at the picture on this one of Anne's it appears to have been taken in daylight but still seems to have some variation in colours and not be completely lilac - I'm not at all suggesting it isn't neodymium, but I think it is rather beautiful that it maintains the intensity and variation in colour.

http://i5.photobucket.com/albums/y195/glassie/misc578.jpg

Is it just a portion of yours that goes lilac in daylight?  or does the whole paperweight go lilac?  From what you said above, I assumed only the middle bit is neodymium but that the glass surrounding that area is coloured but doesn't change colour?
Just interested to know because I have a few pieces of neodymium glass and yours sounds much more interesting than mine! - because it seems to not wholly change colour.  Mind you I like mine lilac but object to them going an aqua blue when I try to put them where I want them  ;D

m
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on January 03, 2011, 12:50:36 PM
Hi,
Finally have taken more colour comparison photos.  Sorry again for the slow reply. 
M - thanks for your comments and the link to Anne's photo.  On my paperweight it is the central region around the bubbles which changes colour.  The colour change is subtle.  To my naked eye it looks soft pink in daylight but in the right-hand daylight photo the difference is very subtle - just slightly more pinky/heather coloured.  I'd be interested in your view and that of lustrousstone as I've not had any neodymium glass before (and maybe still don't  :-\ ).  I wish I had a strongly coloured neodymium piece to compare it with.  I'm going to be on the look-out for one in my future purchases.  I've read that Caithness used neodymium tints so maybe I can get hold of a Caithness neodymium weight to use as an optical standard?
Anyway, I'll be interested in comments on the photo below.
Happy New Year!
Marie.

Title: Re: Sklo Neodymium Paperweight on eBay
Post by: glassobsessed on January 03, 2011, 09:38:24 PM
Here is an example of one colour change: http://www.glassmessages.com/index.php/topic,29702.msg161109.html#msg161109

Not all shades of neodymium glass are the same, searching the message board will provide lots of examples. I think for your paperweight a close up photo in daylight next to one taken under fluorescent light should be definitive (low energy bulb and turn of the flash).

John
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: jakgene on January 04, 2011, 12:42:15 PM
I have one of these identical paperweights, which I have had from new (in 1969) .  Mine doesn't colour change at all though - I have just checked it against the two types of light which change a piece of caithness neodymium glass from turquoise to lavender, and can see no difference in colour on mine.

Not sure if that clarifies anything for you though....
regards

JAK



Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on January 04, 2011, 05:34:00 PM
Hi,
John - I've taken a photo underneath a fluorescent tube and compared it to the daylight photo see below.  Under the tube light the colour is more brown but definitely not blue - is that a definitively no for neodymium then?  That would agree with JAK's observation.  BTW which Caithness design gives you the strong colour change?  I'm on the lookout now for some neodymium glass that I can play around with in different lights, learn from, and use as a comparison for future reference.
Thank you both for your comments.
Marie.
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: glassobsessed on January 05, 2011, 10:13:04 AM
Looks like a no then, which sort of makes sense. Why use neodymium if the colour and or the colour change is hard to see? Nice weight though.

When you do find a bit made of neodymium glass and you take it from daylight into fluorescent light the colour change is immediate and obvious, I almost dropped the lighter in that photo in shock the first time I saw it happen.

John
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: marie anne on January 05, 2011, 12:48:55 PM
Thank you for your reply John.  I love the way your glass changes in your photo.  I'm definitily going to look out for some neodymium glass to play with now.  I like my paperweight and bought it because it was the first czech weight I'd seen.  I mostly buy to sell on but I also love learning about glass and view my purchases as a temporary collection.  I started thinking the weight had a neodymium tint based on a previous thread on glass messages with a similar paperweight.  I'm grateful to everyone who contributed to this current thread.  Thank you for clarifying what I should be seeing with neodymium and which lights to use.
Thanks everyone,
Marie.
 
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: flying free on January 05, 2011, 04:50:56 PM
this is a neodymium paperweight which changes colour but not all of it!  the middle bit stays green and pink, it's only the outer which changes colour.  I didn't put it under a fluorescent light tube but under a long life light bulb.  I'm not quite sure they are the same?
m
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: glassobsessed on January 05, 2011, 06:38:37 PM
They are, the low energy bulbs (with a much longer life than the 'old fashioned' tungsten filament bulbs) are just very small fluorescent tubes, some of today's smaller examples are in the shape of a spiral so that a long tube can be confined in a small space.

You can also get 'light bulbs' which are made with a collection of LEDs (light emitting diodes), these use even less energy than the low energy bulbs but as yet the light given off is not always that bright and tends to be quite 'cold' or harsh.

John
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: flying free on January 05, 2011, 11:42:43 PM
thanks John, well it's not a wonder I hate them then!  I've given up on them except in the childrens rooms where they tend to leave lights on and it's ages before I realise.  I can't stand the light they give off and no one can see what they are doing when we use them.
m
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: flying free on January 16, 2011, 10:31:56 PM
I found this this week - neodymium Jelinek egg - it is in fact paler than the long life photo even but my camera wants to make it darker for some reason  :-\
It's the most amazing shocking pink under normal light.
m
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: misha on January 17, 2011, 06:22:22 AM
They are, the low energy bulbs (with a much longer life than the 'old fashioned' tungsten filament bulbs) are just very small fluorescent tubes, some of today's smaller examples are in the shape of a spiral so that a long tube can be confined in a small space.

You can also get 'light bulbs' which are made with a collection of LEDs (light emitting diodes), these use even less energy than the low energy bulbs but as yet the light given off is not always that bright and tends to be quite 'cold' or harsh.

John

Insomuch as this maybe 'off-topic' perhaps a little info re. the types of lamps [correct terminology] may help in understanding what type of lamp will have the effect that helps identify neodymium enriched glass.

For a start the 'bulb' is the glass envelope which contains the internal components that produce light, be that viable or not.
Some lamps don't need a bulb at all. Some need two layers to reduce Ultra Violet radiation and some to actually have visible light produced.

Fluorescent Lamps:
, so named because of a fluorescent effect making visible light from UV production. It's the florescence of a powder lining a primary bulb that does this.
The UV production comes from the flow of electrical current between metal conductors at each end of the bulb of a tubular construction through a gas inside that bulb.
The gas and phosphor used depends on the colour spectrum produced. Some have a 'warm' colour, some have a 'cool' colour which is close to that of daylight. Some are of specific design for biological effects like those used in butches shops and plant growing applications... a mater of light spectrum produced.
In domestic application the 'daylight' type appear to be brighter.
All fluro tubes light output/efficiency drops over usage time. After a full year of use it's sometimes as bad as 50% yet still work.  This happens in all forms of fluro, be it the straight long fat tubes or the compact spiral or looped type.
Your 'screw' or 'bayonet' domestic lamps that replace older incandescent lamps are correctly termed 'Compact Fluorescent Lamps'  [CFL]
They are available in large sizes [wattage] now of equal size and output to a comparable small/medium rated straight tube. If they are too dim buy the largest you can.
Frankly, these types of lamp are old technology going nowhere. The CFL suffer badly from rapid switching and a buildup of heat in some light fittings that reduces their life.
Better lamps will come soon. They will always have their place in certain applications.
This type of lamp is of medium efficiency, producing more lumens/watt than the older standard incandescent lamps.


Incandescent Lamps:
so named due to a wire element inside the bulb which heats to the point of 'incandescence' and so producing visible light.
Some types of this lamp produce a lot of Infra Red radiation and some produce Ultra Violet requiring a secondary bulb to limit that UV output.
Incandescent lamps include the old bog standard lamp you now replace with CFL and also include the 'Halogen' and 'Quartz Iodide' Lamps which are actually the same.
The term 'halogen' comes from the inert class of gas used inside the primary bulb to prevent element burnout. Iodide type gas is of the halide class chemical. Tungsten is the metal used in most incandescent lamps and in the past a carbon filament element has been used... very rare now but looked great in an old traditional light fitting!
The Halogen type come in a variety of forms [globe and tube] and voltages [12V,110V and 240V] that includes a look-a-like bog standard lamp.  These look-a-like type have an internal and an outer bulb. They are marketed as being 'energy saver' which is an absolute sham/scam because they produce near 50% heat instead of visible light. They may produce more lumen/watt however that is due to the incandescent element glowing far hotter than a standard type. Many small halogen lamps are used in 'down light fittings' and have been the principal cause of house fires when installed incorrectly with regard to heat build-up.  Incorrectly installed roof insulation combined with this also is a huge fire hazard. Sadly insulation install has been incorrectly blamed for house fires here in Australia based purely on malicious political argument. [fact is house fires in insulated homes dropped, but that fact wasn't a biased media friendly fact]
The incandescent lamp will always have it's place in certain applications like oven lamps where heat affects other types. 
These types of lamp are of low efficiency despite the rhetoric of some manufactures/suppliers. The Halogen have a very low life span indeed.... not cost efficient at all.

Light Emitting Diode [LED] Lamps: so called due to being an electronic component that emits certain spectrum light.
These can be in the range of IR, all specific and combined visible light colours and UV.  Your CD & DVD drive uses IR laser LED... your penlight UV torch uses LED... your 'BlueRay player uses both IR & UV laser LED.
These have been widely used in industrial applications for control panel indicators for years. Used in car dashboards these days too. They outlast the small incandescent type which is important for critical monitoring of a machine status.... a blown globe doesn't indicate anything! 
In a domestic lighting application they are currently being used in clusters. They require no glass bulb at all, run very cool and can be spectrum specific depending on application.
Direct consumer voltage [110v or 240V] lamps are available as well as the form to suit a lamp fitting. High output clusters are used for street lighting today.
Currently there is technology in this field which is of far higher light output than the standard LED used in domestic lamps. The manufactures of such high output LED are using them in pocket torches currently instead of domestic applications because that is where they can make the most money selling fancy toys rather than an item that benefits the wider community. Current lamps have some problems that can be addressed by the use of dispersive lenses and wider focus. Colour output can be highly manipulated and controlled. [How many colours do you see on your High Definition LED TV?]
This IS the future of domestic lighting you children will use in the future long after those profit driven manufactures are dead. In some applications they cannot be used due to destruction from heat in the environment they are used [ovens by example]
This type of lamp is of high to very high efficiency. 

With regard to the apparent colour change of neodymium glass, if a specific spectrum fluro tube can have this affect an LED can also have the same affect if 'tuned' to correct light frequency.

With regard to the fluorescence of Uranium glass by UV from a 'fluro tube' [misnomer as they are really a discharge tube with no phosphor] an UV output LED sure has that same affect.
As mentioned previously in this thread, an incandescent lamp will not due to the wide spectrum output and minimal UV content. 
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: flying free on January 17, 2011, 03:10:51 PM
wow!  and thanks  :hiclp:  that is a great explanation.  
Actually a few of my glass pieces look weird under fluorescent light, it definitely changes the appearance - I prefer good old fashioned lightbulbs, but I know their days are numbered.
m
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: misha on January 17, 2011, 04:37:22 PM
No worries.... the confusion caused by the term 'energy saver' is a bit dubious especially when a bright Halogen, short life, heat generating, energy wasting lamp is sold as such. Rather annoying actually. These are good for displaying glass and jewellery because of the intense white light they produce. Thats about all they are good for!
 
Here is an image of a very low quality rubbish type lamp that failed after less than 10hours use. It is dimmed down so I could take the photo. You can see the inner bulb and outer that fell on my lounge... lucky I wasn't sitting there at the time. The metal wires supporting the inner bulb are at 240V This is an electric shock and UV output hazard like so.

http://i756.photobucket.com/albums/xx203/reproducer/Halogenpieceofcrap.jpg (http://i756.photobucket.com/albums/xx203/reproducer/Halogenpieceofcrap.jpg)

I don't have a problem with CFL because I buy the high wattage 'cool white' type that actually have a higher lumen output than those good [subjective] old filament lamps now outlawed here in Australia.

Another type of lamp I didn't mention there was the Discharge Lamps you see used for high powered street lighting, factories and shopping centres. These are of a similar nature to a fluorescent lamp and vary in types of gas used. Their efficiency [lumen/watt] varies accordingly.  I uses a 150W Metal Halide type to light up a 1/4acre car parking area here. The light output is incredible... far higher than what a fluro or incandescent could ever give for that wattage.
Anyhow,  I suspect the light spectrum output of these types of lamp would also produce that colour change in neodymium glass, depending on the type... being  Mercury Vapour [blue bias], High Pressure Sodium [yellow bias] and Metal Halide [blue bias].

I'm like to know exactly what light spectrum triggers this colour change in neodymium glass, an interesting affect to me. From that I may be able to advise the optimum lamp to use.

The other type of glass of interest to me is the diachronic glass.  I have several pieces that use this reflective/filter glass I find very pretty. Fascinating stuff.   
Title: Re: Sklo Neodymium Paperweight on eBay
Post by: misha on January 18, 2011, 05:31:40 PM
More info on Neodymium Glass

http://en.wikipedia.org/wiki/Neodymium (http://en.wikipedia.org/wiki/Neodymium)

Neodymium glass (Nd:glass) is produced by the inclusion of neodymium oxide (Nd2O3) in the glass melt. Usually in daylight or incandescent light neodymium glass appears lavender, but it appears pale blue under fluorescent lighting. Neodymium may be used to color glass in delicate shades ranging from pure violet through wine-red and warm gray.

The first commercial use of purified neodymium was in glass coloration, starting with experiments by Leo Moser in November 1927. The resulting "Alexandrite" glass remains a signature color of the Moser glassworks to this day. Neodymium glass was widely emulated in the early 1930s by American glasshouses, most notably Heisey, Fostoria ("wisteria"), Cambridge ("heatherbloom"), and Steuben ("wisteria"), and elsewhere (e.g. Lalique, in France, or Murano). Tiffin's "twilight" remained in production from about 1950 to 1980.[13] Current sources include glassmakers in the Czech Republic, the United States, and China.

The sharp absorption bands of neodymium cause the glass color to change under different lighting conditions, being reddish-purple under daylight or yellow incandescent light, but blue under white fluorescent lighting, or greenish under trichromatic lighting. This color-change phenomenon is highly prized by collectors. In combination with gold or selenium, beautiful red colors result. Since neodymium coloration depends upon "forbidden" f-f transitions deep within the atom, there is relatively little influence on the color from the chemical environment, so the color is impervious to the thermal history of the glass. However, for the best color, iron-containing impurities need to be minimized in the silica used to make the glass. The same forbidden nature of the f-f transitions makes rare-earth colorants less intense than those provided by most d-transition elements, so more has to be used in a glass to achieve the desired color intensity. The original Moser recipe used about 5% of neodymium oxide in the glass melt, a sufficient quantity such that Moser referred to these as being "rare earth doped" glasses. Being a strong base, that level of neodymium would have affected the melting properties of the glass, and the lime content of the glass might have had to be adjusted accordingly.[14]

Neodymium compounds were first commercially used as a glass dye in 1927 and they remain a popular additive in glass. The color, due to the Nd(III) ion, is often a reddish-purple but changes with the type of lighting, due to fluorescent effects.

The evolving technology, and improved purity of commercially available neodymium oxide, was reflected in the appearance of neodymium glass that resides in collections today. Early neodymium glasses made in the 1930s have a more reddish or orange tinge than modern versions which are more cleanly purple, due to the difficulties in removing the last traces of praseodymium in the era when fractional crystallization technology had to be relied on.

[13] "Chameleon Glass Changes Color". http://coloradosprings.yourhub.com/CrippleCreekTellerCounty/Stories/Arts/Story~443258.aspx. Retrieved 2009-06-06. [dead link]
[14]  Charles Bray (2001). Dictionary of glass: materials and techniques. University of Pennsylvania Press. p. 102. ISBN 081223619X. http://books.google.com/?id=KbZkxDyeG18C&pg=PA102.