Sun is the king of planetary kingdom. When it is benefic in the horoscope then it blesses the native with luck, power, luxury, respect etc but when it is malefic then the native has to suffer defamation, lack of luck and health, lack of self esteem. Following are the mantras to appease Sun:
ऊँ आकृष्णेन रजसा वर्तमानो निवेशयन्नमृतं मर्त्यण्च।
हिरण्य़येन सविता रथेन देवो याति भुवनानि पश्यन।।
ऊँ आदित्याय विद्महे भास्कराय धीमहि तन्नो सूर्यः प्रचोदयात्।
ऊॅं हृीं घृणिः सूर्याय नमः।
ऊॅं हृॉ हृीं हृौं सः सूर्याय नमः।
Ruby is the stone of Sun. To get the positive effects of sun one should wear Ruby. If one is not able to purchase a ruby then garnet, zircon, or agate can be worn. If that is also not possible then one can keep a handkerchief of the same color in his pocket.