I really love this idea, would like to incorporate in the stone in the basement area instead of mosaic risers - I've re thought this and think may be too overpowering. Thinking tiled risers and small pebble mosaics in floor would be much nicer.
DIY - Homemade Gabion wall ie rocks encased in wire baskets and used as a retaining wall - creates a dramatic feature in a garden. No directions on link. Nice someone figured out how to landscape with river rock. I swear they grow!