Interesting: Glass Bead tutorial. My attempt:
Then try say a 300 x 75 strip. Use brushes:
Brush 1: Solid #121212
Brush 2: Gradient#445282 Offset 0%, #29314D Offset 53%, #12131D Offset 95%
Brush 3: Gradient #393F4D Offset 0%, #4A5367 Offset 33%, #5F6A87″ Offset 98%, #626C88″ Offset 100%
Use brush 1 to solid fill lowest layer. On new layer, create a selection on bottom 28.57 % [...]