As per the birth details provided by you, you have born on Sunday, in chtta constellation 1st quadrant under virgo zodiac and Ascendant.
Referring your horoscope, you being fickle minded / varying mindset at the same time dual thinking personality, every time every second for any reason / situation you will endup with two different thoughts. And you being highly tempermental, some times being very calm just like sunami before it shatters it will be very silent. And you will be egoistic, arrogant, lazy, stubborn in nature person. I can also see you being not alright at your health. You are intelligent but not to that extent as what you have mentioned due to the fact that you being lazy and some times move over confident in nature.
As per vimshottari you are under rahu maha dasha from september 2003 till september 2021. And from last august 2011 till last month 3rd of march, you had a pretty good time and from last 3rd of march i. e this month 3rd you started doubting more and you being screwed more about the reliegious believes such as the gemstone what you have mentioned. And you will be in the same deliema till next year march end.
As per the planet transition is concerned you were running with sade sati which is under result giving period which will be there till this november 2014. And even i can see you were been distracted in studies from last december 25th of 2012 and this should be come out after this july 2014.
Seeing all your questions what i see is you have been benefited not because of your blue sapphire nor emerald. You were running with sade sati resulting period from last 1.75 years. As it is under ending period now, it has given you, your desired results. And please take out from your mind that blue sapphrie did good and bad to me. None of the gemstone can give you spectacular results in just few days. Its some marketing guys just giving these kind of false information to people. The gemstone will definately help you coming out of the evil effects of planets not completley but partially it will give you strength to face them.
Frankly speaking wearing blue sapphire will harm in majority of life areas like health, accidents, financial losses all. reason being he is associated with dead against enemy mars who is the lord of eight house and 3rd house and sun who is lord of 12th house. So my advice is just remove all the gemstone for time being till next year march 2015. Later you come back will advice you the right gemstone based on your requirement
First take out your all cock and bull stories from your mind and concentrate on your studies in which you are weak.
And Minnie if i have adviced you blue sapphire i would have taken in to account all the factors, so no need to worry.