Originally produced by Belcher Studios in NJ, this studio was a contemparary of Tiffany Studios. Their process involved a complicated procedure where they actually poured a hot metal matrix in between the pieces.
It was developed as an alternative to leaded glass, and was wildly popular at that time. Composed of tiny triangles and faceted jewels, it sparkles with color. It has a very jewel like appearance.
Unfortunately, they are also very fragile, and are difficult to repair. They are quite rare. I had the pleasure of repairing two of them.