Birthstones by zodiac sign

The older of the two systems — running by sign rather than calendar month, which is why it often disagrees with the one your jeweller uses.

Zodiac birthstones for all twelve signs
Sign Dates Element Stones
Aries March 21 – April 19 Fire Diamond, Bloodstone
Taurus April 20 – May 20 Earth Emerald, Sapphire
Gemini May 21 – June 20 Air Pearl, Agate
Cancer June 21 – July 22 Water Ruby, Moonstone
Leo July 23 – August 22 Fire Peridot, Onyx
Virgo August 23 – September 22 Earth Sapphire, Carnelian
Libra September 23 – October 22 Air Opal, Peridot
Scorpio October 23 – November 21 Water Topaz, Obsidian
Sagittarius November 22 – December 21 Fire Turquoise, Topaz
Capricorn December 22 – January 19 Earth Garnet, Ruby
Aquarius January 20 – February 18 Air Amethyst, Garnet
Pisces February 19 – March 20 Water Aquamarine, Amethyst

Why this list is older

The zodiac assignment came first. First-century writers, notably Josephus, connected the twelve stones of the high priest's breastplate in Exodus to the twelve signs — and the original practice was to own all twelve, wearing each during the weeks it governed.

Wearing only the stone of your own birth is a much later idea, and the monthly calendar version younger still. When the two lists disagree, it is not that one is wrong: they are answering slightly different questions.

Which one applies to you

Zodiac signs cross month boundaries, so the day matters. Born on 5 October, you get opal from both systems and there is no conflict. Born on 28 October, the calendar gives you October's opal while the zodiac gives you Scorpio's topaz.

Plenty of people wear both. Nothing in either tradition requires choosing.