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).
It is not so easy to change fate by wearing a stone.
Rahu generally gives bad results.
Kuja is also giving you bad results.
You have to do penance for a minimum period of 12months.
See my article in google– kumrao99 penance method remedy
for reducing evil planet effect. firstname.lastname@example.org