Price of an Onex will start from Rs300 per carat and will  depending upon all the factors which include CUT, COLOR, CLARITY, ORIGIN/SOURCE & TREATMENTS.
Cut: The cutting of the stone/gemstone does not only improves the beauty of the gemstone but also cover the inclusions. A better-faceted Onex is priced extra over a normal or odd shape Onex. Onex is generally cut in the oval, rectangular, round and mixed cut. Though it is available in different shapes and cut.
Color: Emerad substitute of Onex  is the green to a bluish green variety of the mineral beryl colored by the trace elements of chromium and vanadium. The most desirable onex colors are bluish green to pure green with strong to vivid color saturation and medium to medium-dark tone. An Onex’s color, tone, and saturation direct its value.
Clarity:Â Onex are naturally more involved than most other gemstones. Eye -clean stones are very unique. Unlike most other stones, visible insertions are acceptable in Onex.
Origin/Source: Outstanding in excellent color quality, Columbian Onex range in India extends much ahead than other origins, costing the buyer anywhere between Rs. 300 to  Rs. 500 per carat .Brazilian Onex are comparatively extra affordable.
Treatment:Â Special treatments such as oiling are pleasant in Onex. An Onex treated with strong epoxy-like resins is less precious and valuable compared to the ones with safer colorless oiling.