Reference guides
Birthstones and gemstones by sign
Shops and teachers link gems to Western sun signs, Vedic rashis (signs), and Chinese zodiac animals. Today's Horoscope has a page for each of those twelve signs in each of the three systems.
We skip Tibetan, Celtic, Mayan, and Akan gem lists here. Shared historical charts for those systems are thinner. Read what are birthstones? for a simple overview of all three systems we do cover.
Western gemstones
Western birthstone lists match sun signs and calendar months to gems that jewelers have sold for years. Think diamond for Aries and April, emerald for Taurus, and so on. Shops also sell alternate stones when the "official" gem is too expensive.
Vedic gemstones
In Jyotish (Vedic astrology), certain gems are linked to planets and rashis. Coral often shows up with Mars, pearl with Moon, yellow sapphire with Jupiter, though teachers disagree on weight, metal, and whether you should wear a stone at all.