ri-science:

Why glassblowers use didymium glasses

Glass is made of silicon and oxygen. But there’s another component: sodium. When a glassblower puts a flame to glass, the sodium vaporises, giving a bright orange glow.

To protect their eyes and see the subtle detail of the glass shape, glassblowers wear special didymium glasses. Made of neodymium and praseodymium, didymium glass absorbs the light of the solar flare, acting as a notch filter hiding the orange colour.

Watch the full film here.