Glass Message Board
Glass Identification - Post here for all ID requests => Glass => Topic started by: Anne E.B. on July 05, 2008, 08:54:31 PM
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Any ideas who might have made this 1977 Silver Jubilee pen holder? I would imagine it doubles up as a paperweight also.
On the back is the civic heraldic sheild for Rugby Borough Council with the motto "FLOREAT RUGBEIA MAIOR" (May Greater Rugby flourish) which was granted on 15th March 1976.
Many thanks :)
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Anne,
excuse me for asking, it is glass isnt it?
Its one of those things that sometimes looks like it may be something else,
sorry for asking ;)
Andy
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I was convinced it was glass ::). It felt cold, had surface scratch marks like glass and passed the tooth test ;D. However, your comment has made me look a bit closer. I've removed the cork from the base and have taken a pic. of it compared to the only other 'similar' pieces of glass I have with holes - flower holders, for comparison.
Now I'm thinking it is something other than glass :huh:, as the holes in the pen holder, whilst perfectly smooth and round at the top like the flower holder, are very different at the base. I think the picture will speak volumes. I now think the holes may have been drilled in the pen holder - so can't be glass. What do you think Andy?
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Hi Anne,
whats the tooth test? I dont know that one.
I thought at first , porcelain, but if youre sure its not, and the base doesnt look like it.
It looks glassy, if not, maybe some kind of resin?
Anyone else?
Andy :)
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Different clunk sounds with different materials when gently tapped on teeth ;D I think it was Max who first mentioned the tooth test way back ;D. Not recommended though unless you like having orthodontic treatment ;D, but I have tried it when out and about if I've not been sure, and it works to distinguish between some materials, although I don't know how scientific it really is. I don't think its resin as it feels too cold. I've googled but can't find another one like it.
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I'd say mass-produced plastic (Injection moulded) have you tried looking up the patent, number is fully legible in pic. Decorated by one of the souvenir companies.
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Frank,
i think you mean the number on the black one, i think Annes just used that for
comparison, i dont think theres anything on the pink one.
Regards
Andy
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Oops! Just assumed it was part of the disassembly.
The tooth test and plastics... Many plastics are mixed with a release agent to facilitate high speed production and this tends to migrate from the objects. Only plastics intended for direct contact with food do not use it as it is not particularly wise to allow its ingestion (Most are classed as carcinogens if ingested). Cling film used to contain such agents but to increase flexibilty and self adhesiveness, there was a big scare (70s or 80s) when someone pointed out that people and food packers allowed it to get in contact with food - now clingfilm is very unsticky but safe (well legally neutral at least). So toothing plastics willy-nilly should be done with care even though the risk of ingestion is low.
Tip of a heated pin in an unobtrusive place should give a quick positive for plastic.
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Tried the hot needle test and its not plastic, and I think its too heavy also.
Just thinking out loud... Vitro-porcelain which is glass made to look like porcelain. Is that a possibility? (I bought a reticulated plate initially believing it to be porcelain, but on closer inspection it had the Sowerby mark in the centre). Or, vitreous-porcelain - china which if I understand correctly, can may be look like milk-glass? Or is vitreous-porcelain just the enamel finish? Still trying to think what it might be ::) ;)
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Some plastics are not detected by hot metal and can be very heavy, but other vitreous substances exist.
Quoting an 1880 report in the Glass-Study:
Silica combines with all bases, alkalies, such as potash, soda, and with metals, lead and bismuth. These give it the property to form vitreous compounds. Lime, magnesia, alumina, form with it infusible compounds; the latter, however, mixed with silicates of potash, soda, or lead, furnishes compounds which are suitable for the work of the glass-blower. It is glass proper. If two infusible silicates are mixed together they nevertheless produce fusible glass...
and a Chance patent of 1856 (Glass Study)
Articles are moulded from pulverized vitreous matter, such as collet or waste glass...