gemstone according to kundali
Generally, it is seen that most of the people wear the gemstone without following the simple rules. The thumb rule is that we should always wear the gemstone of Ascendant lord, 5th lord and 9th lord i.e the Trikonadhipati. No ancient book has recommended the weight of the gemstone. However, some modern books and writers are opinion of recommending gems according to the weight of the native. For example: The person with 50 KG weights should use 5 Karats and if the native is 60 KG then 6 Karats. It means 1 Karat should be increased for every 10 kilogram. Lastly, the gemstone of inimical planet should not be used together like Ruby with Blue sapphire and Yellow Sapphire with Emerald.
Ruby
Aries. Leo and Sagittarius Ascendant - Yes
Rest all - No
2. Pearl
Cancer, Scorpio and Pisces Ascendant - Yes
Rest all - No
3. Red Coral
Aries, Cancer, Leo, Scorpio, Sagittarius Ascendant - Yes
Rest all - No
4. Emerald
Taurus, Gemini, Virgo, Libra, Capricorn and Aquarius - Yes
Rest all - No
5. Yellow sapphire
Aries, Cancer, Leo, Scorpio, Sagittarius and Pisces Ascendant - Yes
Rest All - NO.
6. Diamond
Taurus, Gemini, Virgo, Libra, Capricorn and Aquarius - Yes
7. Blue Sapphire
Taurus, Gemini, Virgo, Libra, Capricorn and Aquarius - Yes
8. Gomedh
Gomedh can be used when Rahu is posited in the 3rd, 6th or 11th house in the birth chart.
9. Cat’s Eye
Cat’s Eye can be used when Ketu is posited in the 3rd, 6th or 11th house in the birth chart.
These all are very generalise experience two wearing Gemstone, if you would like to wear. However, many other parameters still needs to checked.