Vintage 10K Yellow Gold Yellow Green Semiprecious Stone Solitaire Ring 6 [r291]

-this beautiful vintage ring features a yellow/green/brown semiprecious gemstone of unknown origin. The stone tests in the mid-range area, somewhere around topaz/spinel but I am unsure what exactly it is
--set into 10k yellow gold
--size 6
--3.9 grams in weight
--marked "ESEMCO" and other obscured markings; acid tested
--band width is about 2.3 mm at back and 15.3 mm in front
--in very good preworn condition with light normal wear.
--gift box included upon request
--Photos enlarge jewelry and show it in close-up format. Refer to dimensions and measurements given for actual size

198[EZ-R291]