Topic: imperial slag glass

[RAY]

these are the only glass bit's i got today, i think there tooth pick holders, marked on the inside IG and also on the button on the base, on one of them there's a sticker thats says PURPLE SLAG GLASS CIRCA 1850 BY IMPERIAL surley these aren't that old or are they

click image

[Frank]

I am intrigued by Slag glass, having only learnt of it this year. Does this glass give any UV reaction?

[David E]

Not UV reactive to the best of my knowledge.

A modern label, and I think it's wishful thinking on their behalf to suggest 1850. I had always thought production was first developed around 1880, with Sowerby being the first British makers. Ivo's book suggests c.1870 in Venice or Germany.

[KevinH]

Frank - you've only learnt of slag glass this year? Not seen the examples in my web page (2001), then? (All photos in that page are clickable for larger versions with descriptions.)

The coloured parts of slag glass are unlikely to fluoresce, but the white (opal) parts can do so. This image shows my items under shortwave uv - with the white and purple items glowing pale blue (although in the image they may look like "bright white"). Look very closely and you may also see that several of the items have small patches of "blue" uv reaction - but not the overall "bright dots", which are just the standard uv reaction of dust (even though these items have been in a cupboard for some time!).

Under longwave uv, the white parts do show some green fluorescence but it's quite weak.

[uphoosier]

The 1850 is a typo. Probably meant to type 1950. Imperial began production in the early 1900s.  They began making slag glass in the 1940s or 50s, and started using the I over G mark in 1951.   They closed in 1984.

[jsmeasell]

I edited the three-volume Imperial Glass Encyclopedia and can provide this information about this firm's "slag" colors.

Purple Slag debuted in 1959. The 1850 on the label is not a typo, as Imperial also had printed hang tags and other point of purchase materials which used this date, albeit historically inaccuate.

Caramel Slag began in earnest in 1964, although some ashtrays had been marketed 2 years earlier. Some Imperial materials for consumers mistakenly atttributed the color to Harry Northwood.

Jade Slag started in 1975-76 (again, some ashtrays were made earlier).

Ruby Slag started in 1969.

Most pieces are marked with the IG mark or one of the later marks: LIG and ALIG

[Frank]

Frank - you've only learnt of slag glass this year? Not seen the examples in my web page (2001), then? http://www.glassmessages.com/index.php/topic,17722.0.html

I meant Slag as in :

slag as used in "slag glass" is specifically blast furnace slag, a residue product from the smelting of iron ore.

see also http://www.glassmessages.com/index.php/topic,17722.0.html
I will still be transcribing that article I mentioned.

[RAY]

thanks for the comments all

Frank do you want a piece of slag glass, there's tons of it where i live,

here's a bit of mine as you can see there's some iron bit's that have gone rusty

click image

[Frank]

Different sort of slag Ray. :-)

[RAY]

Different sort of slag Ray. :-)

it's iron ore blast furnace slag