This set is crafted from an extraordinary type of glass known as Alexandrite, or Neodymium glass.
 
Alexandrite is unique as it displays two different colors depending on the light source. When you hold these glasses under the sun or warm light, they radiate a vibrant purple hue. However, when placed under white, fluorescent lighting, they transform into a stunning shade of blue. This captivating color change is attributed to the neodymium oxide present in the glass. 
They come from Italy.