Gemstone Calculator
Which of the nine stones your rising sign licenses, which it refuses, and why. A gemstone strengthens its graha, so it is the one remedy that can be pointed the wrong way.
Your rising sign
The lordship rule needs exactly one thing, and this is it. If you know your lagna, choose it. If you do not, give your birth and it will be computed.
The classical carat rule is one ratti per twelve kilograms of body weight, one per ten for emerald. Leave this blank and you get the classical band instead of a number invented about you.
Stones you already wear
Tick two or more. Whether a pair clashes is a property of the stones and not of your chart, so this needs no birth details. The matrix is derived from the classical friendship table rather than copied from a list, and every verdict shows the relation behind it.
Pick at least two to see the pairwise verdicts. Of the thirty-six possible pairs, 15 are refused by the friendship table and 5 more circulate as incompatible without it.
The nine navaratna
One stone per graha. Which of them are yours depends entirely on your rising sign, and no stone is licensed for more than a quarter of ascendants.
| Stone | Graha | Colour | Band | Metal | Finger | Day | Substitutes |
|---|---|---|---|---|---|---|---|
| Ruby (Manik) | Sun | Deep pigeon-blood red | 3-5 carats | Gold | Ring finger | Sunday | Red Garnet, Red Spinel, Sunstone |
| Pearl (Moti) | Moon | White with a soft lustre | 4-7 carats | Silver | Little finger | Monday | Moonstone, White Coral |
| Red Coral (Moonga) | Mars | Vermilion to ox-blood red | 5-9 carats | Gold/Copper | Ring finger | Tuesday | Carnelian, Red Jasper |
| Emerald (Panna) | Mercury | Grass to deep forest green | 3-6 carats | Gold | Little finger | Wednesday | Peridot, Green Tourmaline, Green Jade |
| Yellow Sapphire (Pukhraj) | Jupiter | Lemon to golden yellow | 4-7 carats | Gold | Index finger | Thursday | Yellow Topaz, Citrine |
| Diamond (Heera) / White Sapphire | Venus | Colourless and brilliant | 0.5-1 carats | Silver/Platinum | Middle finger | Friday | White Sapphire, White Zircon, White Topaz |
| Blue Sapphire (Neelam) | Saturn | Cornflower to royal blue | 4-7 carats | Silver/Iron | Middle finger | Saturday | Amethyst, Iolite, Lapis Lazuli |
| Hessonite (Gomed) | Rahu | Honey to cinnamon brown | 5-8 carats | Silver | Middle finger | Saturday | Orange Zircon, Agate |
| Cat's Eye (Lehsunia) | Ketu | Honey-grey with a moving band of light | 5-8 carats | Silver | Middle finger | Saturday | Cat's Eye Quartz, Tiger's Eye |
What this page will not do
This page names stones and never sellers. It carries no prices, no vendors and no certification bodies, because the site does not sell gemstones and should not read as though it does. A gemstone is a strengthening remedy, so it is the one remedy that can be pointed the wrong way; where the rule refuses a stone, the mantra, the daan and the fast are given in its place and they propitiate without strengthening.
Why a Gemstone Needs a Rising Sign
Every other remedy in Vedic astrology is propitiatory. A mantra, a donation, a fast โ these settle a graha down. A gemstone is the exception: it strengthens the graha it belongs to. That single difference makes it the one remedy with a direction, and a direction can be wrong.
Whether it is wrong depends on which houses the graha rules for you, and that is fixed by your rising sign and by nothing else. Saturn owns the 4th and 5th for Libra rising, which makes it a yogakaraka and blue sapphire the safest stone that chart has. The same Saturn owns the 6th and 7th for Leo rising, with no trine at all, and the same stone feeds the difficulty instead of the remedy.
This is not a marginal case. Every sign-owning graha is licensed for exactly three of the twelve ascendants and refused by exactly three โ an arithmetic consequence of there being three trines and three difficult houses, not a matter of opinion. No stone is right for more than a quarter of readers, and a page that recommends one to everybody is wrong about three quarters of the time.
What are the nine gemstones of Vedic astrology?
The navaratna are one stone per graha: ruby for the Sun, pearl for the Moon, red coral for Mars, emerald for Mercury, yellow sapphire for Jupiter, diamond for Venus, blue sapphire for Saturn, hessonite for Rahu and cat's eye for Ketu. Each carries its own metal, finger and weekday, and its own beej mantra with a fixed japa count.
The nodes sit slightly outside the system. Rahu and Ketu own no sign, so the lordship test that licenses or refuses every other stone cannot be applied to them at all. That is not the same as the stones being safe: it means the rule has nothing to say, and hessonite or cat's eye should be worn on specific advice rather than as a default.
What are the life stone, lucky stone and benefic stone?
The life stone (janma ratna) belongs to the lord of your 1st house. It supports the body, the constitution and the sense of self, which is why it is the one worn for life rather than for a season. The lucky stone (bhagya ratna) belongs to the 9th lord โ fortune, dharma, the father and the teacher. The benefic stone (karyasiddhi ratna) belongs to the 5th lord โ intellect, creativity, children and the results of work already done.
A property worth knowing about the triad: the three can always be worn together. The 1st, 5th and 9th are 120ยฐ apart, so they are always the three signs of one element, so the triad is always that element's three lords. Fire gives the Sun, Mars and Jupiter; water gives the Moon, Mars and Jupiter; earth and air both give Venus, Mercury and Saturn. Those are precisely the natural friendship groups, which is why no ascendant's three stones are ever at odds with each other.
Which gemstone is refused for which ascendant?
A graha is a functional malefic when it owns a difficult house โ the 6th, 8th or 12th โ and no trine. Its stone is refused there. Blue sapphire is refused for Cancer, Leo and Pisces rising; ruby for Virgo, Capricorn and Pisces; yellow sapphire for Taurus, Libra and Capricorn; diamond for Scorpio, Sagittarius and Pisces; pearl for Leo, Sagittarius and Aquarius; emerald for Aries, Cancer and Scorpio; red coral for Taurus, Gemini and Virgo.
Notice the shape: three refusals per stone, three licences per stone, and every one of the twelve ascendants left with at least one stone it can wear. Pisces has three, which is the most any ascendant gets. Aries, Gemini, Libra and Aquarius have exactly one. The average across all twelve is 1.75 licensed stones out of nine.
When should a gemstone be worn for the first time?
Four conditions: the stone's own weekday, the waxing fortnight, the hora of its own graha, and the hours after sunrise. The first hora after sunrise always belongs to the lord of that weekday, so on the stone's own day the graha's hora is the one that begins at sunrise โ which is why the classical instruction is simply "at sunrise on that day".
Before wearing, the set ring is soaked overnight in raw cow's milk or Ganga jal, rinsed at dawn, placed before the household deity with incense, a lamp and unbroken rice, and energised with the beej mantra at its prescribed count โ 7,000 for the Sun, 11,000 for the Moon, 19,000 for Jupiter, 23,000 for Saturn. Then it goes on straight away.
How the Gemstone Calculator Works
From a rising sign to three stones and six verdicts
Give Your Rising Sign
Choose it directly if you know it, or enter your birth and it is computed.
Lordship Is Resolved
Which houses each of the nine grahas rules from that ascendant.
The Triad Is Named
Life stone from the lagna lord, lucky from the 9th, benefic from the 5th.
All Nine Are Judged
Licensed, split, neutral or refused, each with the reason.
What This Calculator Returns
Including the answers that cost us a sale
The Refusal, at Full Weight
Where the rule says no, the carat grid is suppressed and the mantra and daan are given instead.
The Split Verdict
Fifteen of the thirty-six triad slots are a trine lord that also owns a difficult house. Most pages hide this.
A Derived Conflict Matrix
Which stones clash, computed from the classical friendship table, with the relation shown for each pair.
A Solved Wearing Window
Not "a Thursday morning" but which Thursday, that day's sunrise, the graha's hora and the actual tithi.
Frequently Asked Questions
What people ask before buying a stone
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What to read next
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Pawan Acharya ยท Acharya (Vedic Astrology)
Vedic Astrologer & Nadi Shastra Researcher
Pawan Acharya (Acharya Pawan Chandra) is a Vedic astrologer and Nadi Shastra researcher with over 35 years of experience. He is the author of several classical Jyotish works โ including Vivaha Sutram, Samay Sutram, Phalit Sutram and Jyotish Ke Anubhoot Rahasya โ and developed an original method for calculating the probable date of marriage from a person's birth details. His research has contributed to leading astrology software and journals.