You indeed have a libra ascendant but Saturn and Mars are very far apart (20 degrees and hence despite being in one house no conjunction).
Wearing a ring will not change luck or destiny but hardwork/intelligent decisions will. If you still want to wear a ring to feel good, from career pov Diamond/Emerald/Rahu stone are good but go for Rahu’s stone as Rahu is in nakshatra of Moon and has Sun as sublord denoting excellent combinations for career (Sun and Moon are lords of 11 and 10 houses) and currently you are under Rahu Mahadasha till 2027 (Mahadasha lord has most influence).
God bless,
Astrologer Deepak