Gemstone Calculator
A gemstone recommendation starts from the Lagna, not the Moon sign — which is why the birth time is needed. And knowing which stone is not for you matters as much as knowing which is — both are given below.
What this calculator tells you
This tells you which gemstone suits your chart — and just as plainly, which one does not. The second half matters no less than the first, and it is the half usually left out.
How the calculation works
The recommendation starts from the Ascendant, not the Moon sign — which is why a birth time is needed. The Ascendant lord’s stone comes first; the tradition calls it the life stone. The yogakaraka planet for that Ascendant is considered next. Planets that are functional malefics for the Ascendant, per the classical tables, have their stones placed explicitly in an avoid list.
How to read the result
The result comes in two parts — stones to wear, and stones to avoid. Ignoring the second is the most common way people come to harm. A rudraksha suggestion is included as well; it is a separate thing, not a substitute for a gemstone. A stone is not a cure — and anyone selling it as one is worth being wary of.
Common questions
Why not choose a stone by Moon sign?
Because a stone is tied to a planet’s strength, and a planet’s role is set by the Ascendant. The same planet can be a yogakaraka for one Ascendant and a maraka for another.
Should a weak planet’s stone be worn?
This is the most damaging misconception. If that weak planet is a functional malefic for your Ascendant, its stone will do harm. That is exactly why the avoid list is given separately here.
Can I just wear it without consulting anyone?
The page gives a recommendation. But a gemstone is an investment of money and time — having it checked once is sensible.