Spectra of Neon Plasma Glass: a double walled glass mug glows orange and blue from the excitation spectrum of neon gas at low pressure. How can we know the gas is neon? A diffraction grating splits the light up revealing the famous emission spectrum of the element- you can see a prominent violet line and a bright green line as projected images of the illuminated filaments. The famous yellow and red lines of neon are visible only at the ends of the fractal like filaments. The base contains a high