Shine a flashlight through the glass or hold it up to a light source. Crystal will prism, forming a rainbow where the light shines. Glass will not. Use your fingernail to flick the edge of the glass.

The key is knowing if they're original. Vintage glass prisms (those adorable chandelier-style crystals) usually hang off the holder directly or hang from a plate under the candle called a bobeche.

rainbow prism effect when held up to the light, thinner than regular soda-lime glass and heavier than regular soda-lime glass. -Crystal with a lead content over 35 percent will actually sparkle.

We specialize in producing crystal optics mainly made of SAPPHIRE, Fused Silica, Glass, Silicon and coating. Products include windows, Plano-Convex/concave lenses, spherical lenses, prisms, rods & ...

The exhibition is planned to last until the end of June. Approximately 9-meter-high stained glass made with 500 crystal prisms will be filling the space with rainbow colors as the light shines on it.