Vivid green and bright fire indicate peridot (olivine). The facets catch the light quickly, giving a pleasant, citrusy sparkle.
The notched rail lightens the silver and adds air. Local irregularities in the lugs speak volumes: hand-set, not band-set.
It comes from Pakistani workshops, where the silver (approximately 80%) has a patina instead of a mirror polish. This gives the ring character from day one.
Peridot is also called olivine – the green pairs perfectly with linen, white, and light denim.