Topic: Spectral analysis to determine origin of glass

[uphoosier]

I was rereading McKearin's American Glass published in 1941, and was struck by something.  He postulated that in the near future (from 1941) he expected that spectral analysis would be possible as a means of identifying glass.  He said that sand is one common ingredient that would be sourced locally by a glass manufacturer.  Each region's sand would have distinct impurities.  Spectral analysis for unique impurities would allow for identification of the sand used to manufacture the glass and at least give solid attribution to a region.  Anyone ever hear of any attempts to accomplish this?  Sure would solve a lot of English - Italian - Bohemian _ Scandinavian  mysteries.

[pamela]

My Husband and me had that regarding a bronze figurine he owns and I was told, he could determine glass with +/- 500 years !  Guess still no chance for glass of the last 200 years to be attributed by him or them 

[KevinH]

He said that sand is one common ingredient that would be sourced locally by a glass manufacturer.

If only it was as simple as that! I am sure that the glassmakers who visit the board would be able to say why that idea was not generally taken up by glassworks around the world. My interpretation of things is that just because all sand is silica does mean all sand is good for glassworking.

[Fuhrman Glass]

I don't think this conjecture ever really worked as in the last 70+ years there has been additions of all sorts of elements and metals to the basic glasses that would throw a whole different set of findings on then outcome of mass spectrometer results.
Selenium, manganese, amd other elements will change the color and clarity of many glasses and combinations of different elements make dramatic changes innthe glasses.
This theory may work if you were strictly dealing with clear glasses that were produced before 1800 or earlier. Before this time they used little additional elements to change their basic glasses.
In todays world, chemicals and even basic sands and batches for glass are shipped all over the world and can end up in places you'd never suspect.
i.e. I saw a German company in Corning, NY last week offering clear cullet made in Germany or some where in the EU to lots of glass studios in the US. Phillips and several others have been doing this for many years. The Italians have shipped their raw glass to many different countries for several hundred years  where it was remelted. Even the Egyptians in ancient times made colored glasses that were shipped all over to be remelted and fabricated in to beads and small core vessels.

[malwodyn]

I've been thinking about the possibilities of glass analysis for some time.  Fuhrman Glass makes a very serious point about the extent of world-wide trade, and the effects that this would have on contemporary production.  It does not however mean that we cannot learn a great deal from scientific study particularly of historic glass - and particularly if we can apply non-destructive methods such as spectrographic analysis to authenticated pieces of known provenance.  It could help us to authenticate doubtful pieces, as well as demonstrating that a suspected fake is indeed so.  Scientific study is not the answer to every question - it allows us to shed a little more light on the picture.  It is not only materials that move around - so do glassmakers - Bohemian glassmakers went to Stourbridge, Frederick Carder went from Stourbridge to Corning, Salvador Ysart moved from Spain to France to Scotland.....

The possibilities of scientific study of glass are enormous; unfortunately the equipment needed for a laboratory does not come cheaply, and the major manufactures who might be able to fund such equipment are likely to be using it for their own work.  Even an academic institution would find it difficult to justify the investment today, if it were purely for the study of glass.

[Frank]

Sufficiently accurate spectrographs can be home made easily, (google, used to be a discussion/link in cafe but it seems to have vanished.)  With a bit of rigour and a manufactured diffraction grating could easily generate useful results for comparing glasses that otherwise appear to be of similar source date.

[krsilber]

One problem is that the glass produced by a company changed over time.  Not only did the major constituents change, their sources did as well.  Even if you could identify trace amounts of impurities, you don't know whether they are coming from the sand or some other ingredient.  Multiple companies also likely used some of the same sources.

I don't think the McKearins' statement the sand was acquired locally is a safe assumption.  Otherwise you might be able to compare the sand nearest the location of the company and look for similarities, but some sand was shipped hundreds of miles.

On the other hand, there might be detectable broad geographic or production date differences across a range of glasses, for example the presence of manganese or lead.