Is Boro the same as Crystal?

[SallyB]

Hello

I hope this is the right place for this question.

Sometimes when I'm using some boro it briefly gets the sort of cloudy look that Lalique crystal has.  I love this look and wonder if boro is the same as crystal and I just am not knowledgeable enough to know.

I thought someone might know the answer.

Thank you
Sally

[Hamilton Taylor]

No.
Boro is short for borosilicate.
"Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are known for having very low coefficients of thermal expansion (~3 × 10−6 /°C at 20°C) (edited to add, we would say coe33), making them resistant to thermal shock, more so than any other common glass. Such glass is less subject to thermal stress and is commonly used for the construction of reagent bottles. Borosilicate glass is sold under such trade names as Pyrex and Simax."
More about borosilicate here.

The term Crystal usually, though not always, refers to a soft glass with excellent optical properties and a high refractive index, usually as a result of its lead content.
Here's some more about lead crystal.

I think the cloudy look of Lalique is due to sandblasting, but am not sure. If I'm thinking of the same stuff you are, the cloudy look on the surface of clear boro when you are working it is due to the stretching of the cooling surface, causing a network of microfractures. It polishes off with more heat, which is why you are only seeing it briefly.

Hope this helps,

Sean

[stuwaudby]

Just had a look at the video on the Lalique website and it definitely isn't boro. Alot of it is etched, is that what you mean by the effect? (Crystal is any type of glass, but usually ground.)

[SallyB]

Thank you Sean and Stu(?)
That's really helpful.  The look must just be from etching.  I thought it was something more than that.  I bought my mum a fish years ago and it has a look about it that doesn't look like etching but I'm not an expert.

I'll have to splash out on some etching stuff when I get an influx of cash - I live in hope!

Thanks again
Sally

[garishglobes]

Hmm. Quite a lot of the glass that you see in Hungary has a 'cloudy' look. Like some of the boro colours (the amber purples), it reflects and transmits light differently - blue in reflection, brown in transmission (or possibly the other way round). Some of the Lalique I've just looked at seems to have that same kind of effect... in which case, it would be caused by the addition of chemicals to the glass. I would love to have this as an available boro colour.

But it still absolutely, positively, definitely ain't boro!

[Flyingcheesetoastie]

The Lalique effect is from Opaline glass which is incredibly difficult to achieve in casting. Bullseye have just made a type of it but many of the Lalique receipes are unique.

[Glyn Burton]

I recently had the chance to get "up close and personal" to a lot of Lalique glass. Lalique did the fittings for a church here in Jersey (font, rood screen, doors, windows etc) and its being restored. The glass is opaline I think its fluorine which is added, but I think the surface has been etched and then partially acid polished. Its a fantastic surface but the process is far too dangerous for a clumsy b-----r like me.

As a bye the bye my wife's uncle remembered meeting Lalique when he was supervising the unpacking of all the glass he said he was a nice bloke and happy to chat!
In case you are interested
www.glasschurch.org