A very simple answer to this question is that there are no specific gemstone which gives peace of mind and success.
Gemstones for health and wealth
The word peace and success is a VARIABLE WORD and the meaning of it will differ from person to person as every person see it from their point of view. What is success for a person may not be same for other person, because the every person view it as per his need in life.
For example a person lost his peace of mind due to many reasons like :
1. Health issues
2. Wealth issue
3. Education isuue
4. Child birth issue
5. Marriage, love break issue
6. Career problems
7. Problems at job
8. Unable to own a home
9. Unable to travel abroad
Fi Finance issues
11 Etc etc etc etc etc
So it is seen that how a person can lose his peace due to so many events in their life.
So when a native ask an astrologer such questions then the astrologer study his horoscope to see which is the planet responsible for such disturbance in the life of the native.
Gemstones for success in life and career
Then co-relating with the present mahadasha the astrologer study which can be the best remedy to pacify the negative impact of that planet for the ASKED EVENT BY THE Querent and decide the gemstones for success in life and career growth.
Stones for money luck
THE REMEDY WILL DIFFERE FROM PERSON TO PERSON FOR THE SAME EVENT AS THE PLANET RESPONSIBLE FOR THAT EVENT WILL DIFFERE FROM PERSON TO PERSON AS PER THEIR HOROSCOPE.
So what could be a remedy for native for his marriage issues NEED NOT BE SAME FOR THE OTHER PERSON HAVING SAME ISSUES.
So it is understood that there CAN NOT BE A SIGNLE COMMON GEMSTONE FOR PEACE AND SUCCESS FOR EVERY PERSON.
Crystals for fame and success
A good astrologer will study the whole horoscope and then only identify the gemstone needed for the native as per his horoscope and his need for that event.
Most powerful stone to attract money
Nothing is ready made or custom made in astrology as in there are so many variable parameters in astrology that no astrologer can HAVE A DIRECT CONTROL OVER IT. IT IS ONLY AND ONLY CONTROLLED BY GOD HISSELF.