JUNIPER RIGIDA - ROOT OVER ROCK - PREBONSAI

Tree: Juniper rigida - Juniperus rigida
Pot: Cascade plastic flowerpot.
Height: 12 cm.
Age: Unknown.

After repotting - three years ago:

The rock (inside the pot) from my old aquarium:

Last year:

 The moss.

I wonder how look the roots over rock after these three years. But I'll wait with it to the next year.