Gemstones are channels for cosmic energy. The planets all emanate vibrations and frequencies that can directly affect our physical beings and energies in positive or negative ways. Gemstones can be used as mediums to either counteract or enhance those effects and establish balance.

One of the most common misconceptions about gemstones is that the stone that corresponds with your birth month is your birthstone and will have the luckiest effect on your life. In actuality birthstones have to be clearly aligned with your Vedic birth chart and the effects of certain stones at certain periods of times can change according to your chart.
Your ruling planet and its compatible neighbors and their corresponding gemstones can all bring fortune but combined with timing and planetary positions their affects can become weakened or their negative influenced strengthened.

Saturn is the ruling planet of Capricorn whose corresponding gemstone is Blue Sapphire. Blue Sapphire represents discipline, self-care, humanity, commitment, and spirituality. 

Planets that are not friendly to Saturn and the Capricorn ascendant include the Moon, Sun and Mars. Therefore a person born under Capricorn ascendant should avoid wearing Ruby, Pearl and Red Coral gemstones. Planets that are friendly to Saturn and the Capricorn ascendant include Venus and Mercury. Therefore a person born under Capricorn ascendant can wear Blue Sapphire, Diamond or Sapphire and Emerald gemstones.

Deducing which gemstones to wear and for how long and when to actually wear them require a deeper look into your Vedic birth chart. You can book and appointment online to determine which gemstones are right for you.