Colours in Glass

Over the years - you pick up some info about the metals used to make the colour in glass. You learn early on that gold makes pinks and purples - and when the price of gold shot up - we saw the price of the purples and pinks shoot up too.

The ivories and yellows are sulfur-based - and they react with the copper-based colours - the greens and turquoise blues.

Tin gives you white, and manganese gives you black, and some of the browns are made with gold too. Chrome was used for the reds - although for health reasons - other elements have been found. Ditto for the colour we know as cobalt blue.

However, while reading Discover¹  - I came across a very interesting article on the "Rare Earths" - a category of elements that are neither particularly rare nor earthy. It's a good article - worth reading.

However - the part that really grabbed my attention was this passage:

Glass doped with cerium oxide effectively absorbs ultraviolet light ... . Two other rare-earth metals, neodymium and praseodymium, work their magic at the other end of the spectrum. They impede infrared light and so are incorporated into welders' goggles to protect workers eyes from the heat. These oxides also absorb yellow and green, so glass made with them has a characteristic mauve tinge. 

Geez  - could you describe our didymium lenses any better? Ooo - Di - meaning two - neodymium and praseodymium.

That explains that.

But wait - it gets better.

More broadly, rare earths add colour ... . Glazes on earthenware dishes contain oxides ... tin (white), copper (blue) or iron (amber). But rare-earth oxides ... create more exotic hues, such as pink and lime green. ... erbium oxide ... gives a subtle tone -  more pink lemonade than Pepto-bismol.

 So think about those fabulous new pinks that we have seen, like the Pinks from CiM - Gelly's Sty - a pink like no other in any of the other glass palettes.

Hmmm. Veddy interesting.

I realized that this information may not buy you anything - but I still think it is fabulous to know this stuff!



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¹Discover Magazine, "Elements of Modern Style," by Hugh Aldersey-Williams. pp 62 - 67