Before we can understand the influence of planetary gems and other upayes we first have to understand the nature of our universe. The Sages teach us that the vibration (primordial sound) of the universe is in constant flux - the beautiful celestial song of the universe is unique to each living being.
Bija (meditation) mantras correspond to the specific sound or vibration of the Universe at the time (and place) of our birth and its taught that meditating with the primordial mantra corresponding to Moon's nakshatra guides us effortlessly back to our own essential nature. Seeing the essential nature of the Universe as pulsating sound or vibration we can more readily understand the relationship between precious gems and their ruling planets. The vibration of Ruby is non-different to that of Sun. Pearl to Moon, Red Coral to Mars, Emerald to Mercury, Yellow Sapphire to Jupiter, Diamond to Venus, Blue Sapphire to Saturn etc..
In this same way mantras specific to the planets help to lessen the effects of our karma - its the vibration of the sound that has the effect - moreso than the meaning of the mantra. Gems of course are not available for everyone and by the grace of God we have been given the mantras corresponding to each planet. If recited in the prescribed manner they are as effective as gems. The difference between the two remedies is that one requires money while the other requires effort and dedication to complete the required number of repetitions.
Sages declare; "The Sun moves in me, the Stars move in me, the Moon rises in me, the whole Universe is in me. Those who know this great truth cry in ecstasy, *AHAM BRAHMASMI*, I am the universe, I am the existence."
Wendy Vasicek, PGA