GEMS AND PLANETS

In Hindu Astrology, there are 9 planets considered for analysing a horoscope, and therefore, there are  nine different gemstones assigned to them. These gem stones are called Nav-ratnas or "Nine Gems. The planets and their stones are:

PLANET	GEMSTONE	SUBSTITUTE
Sun (Surya)	Ruby (Manik)	Red Garnet
Moon (Chandra)	Pearl (Moti)	Moonstone / Opal
Mars (Mangal)	Red Coral (Moonga)	Carnelian
Mercury(Budha)	Emerald (Panna)	Peridot
Jupiter (Guru)	Yellow Sapphire	Topaz (Golden)
Venus (Shukra)	Diamond (Heera)	Crystal
Saturn (Shani)	Blue Sapphire (Neelam)	Lapis Lazuli / Turquoise
Dragon's Head (Rahu)	Gomedha	Zircon
Dragon's Tail (Ketu)	Cat's Eye (Lahsunia)	Alexandrite