Dichroic glass JewelryWhere the name comes from: Glass that contains microscopic layers of metals or oxides cause light to be split into different wavelengths or colors. There is one transmitted color and another different reflected color.
Where the stones come from: Manufactured by layering metals and/or metal oxides onto glass.
Chemistry: Gold and silver metal may be used as well as oxides of magnesium, chromium, titanium, aluminium etc. The specific result is not totally repeatable so each piece of glass is unique.
Colors: Any and all, multiple colors are shown by any given piece when viewed from different angles.
...and another thing: Dichroic glass was developed as a filter by the aerospace industry.