Depending on the light this ring can look black or have a navy blue tint.
With normal lighting I would say it is more of a dark navy blue color.
Pietersite spirital meaning:
It is said to center on the spiritual being with the ability to ground an individual to the etheric body - the first or lowest layer in the "human energy field" or aura. Pietersite discharges negative energies an emotional turmoil while cleansing the aura, restoring it to calm.