Himanshu,
read Mr. TMR’s blog as I also believe that gemstones cannot replace hardwork, discipline and effort nor they can create shortcuts/give extra luck (else karma theory will fall on its face).
Still if you want to wear it for moral boost/optics, I concur with Mr. Navneet ji that Blue sapphire works the best. Saturn is placed in nakshatra of Jupiter with Rahu as sublord showing powerful combination i.e. 2,10,11 for professional success (also Saturn being lagnesh is always benefic and placed in 9th house in Chalit). Venus is yogakaraka but has no powerful combination for professional success.
God bless you with hardwork and logic,
Astrologer Deepak