Dear Tarpan,
Can you please explain me how the saturn becomes yogakara in your horoscope? He is in purva punya stana which is 5th house and when there is malefic planet in your previous incarnation house, then you should face the evil effects from your past birth and how it could be beneficial to you?
I will recommend the gemstone for your particular problems so it would be better if you could mention why you are looking for gem therapy?
GOD BLESS!!!
Srinivasa Temkar