There are 9 Precious gemstones representing the nine Planets. They are also referred as ‘navaratna’ which is a Sanskrit term which means ‘nine gems’ or ‘a jewelry set with nine gems’. These stones are popular and well known. The navaratna or nine gemstones representing the navagrahas or nine planets are Ruby, Pearl, Yellow Sapphire, Emerald, Diamond, Red Coral, Blue Sapphire, Gomedh and Cats Eye.
There are several stones which are as popular and costly as the precious ones.I have written about most semiprecious or substitute stones like agate, amazonite,amber, ametrine, amethyst,aventurine, aquamarine, bloodstone, carnelian,Chrysocolla, citrine, crystal, fluorite, garnet, hematite, iolite, jade, jasper, kunzite, lapis lazuli, malachite, moonstone, onyx, peridot, sodalite,spinel, tanzanite, topaz, tourmaline, turquoise and zircon.
Find more on these gems individually in my HubPage Article 'Precious and Semiprecious Gemstones'.