In Jyotish, gemstones (ratna) are a primary remedy: each of the nine planets resonates with a specific stone — 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. Wearing the right stone is said to amplify that planet's positive influence in your life.
The crucial point most people miss: your gemstone is chosen from your ascendant (lagna), not your Sun or Moon sign. Your life stone is the gem of your ascendant lord, and the truly beneficial stones are those of your chart's functional benefics — the planets that rule auspicious houses for your specific rising sign. A stone that is lucky for one ascendant can be harmful for another (Jupiter's Yellow Sapphire, for instance, is a benefic for some lagnas and a malefic for others).
This calculator reads your exact ascendant, identifies your life stone, and separates the gems that strengthen your chart from those you should avoid. Gemstones are powerful remedies — especially Blue Sapphire and Diamond — so always confirm the precise stone, weight, metal, and timing with a full chart reading before wearing one.