January garnet

February amethyst, hyacinth, pearl    

March heliotrope, jasper    

April diamond, sapphire    

May emerald, agate    

June cat's eye, turquoise, agate    

July turquoise, onyx    

August sardonyx, carnelian, moonstone, topaz    

September chrysolite    

October opal, aquamarine    

November topaz, pearl    

December heliotrope, ruby  



Early civilizations, such as those in India and Babylon, have  attributed gemstones with magical properties and especially to their  relationship with the signs of the zodiac. Over time, astrologers  assigned gems of certain colors to the twelve signs of the zodiac to  help people influence the planets in their favor. 

Tropical zodiac

 Sign                         Dates                          Stone   

Aquarius    21 January – 21 February      garnet

Pisces        22 February – 21 March         amethyst   

Aries          22 March – 20 April                heliotrope   

Taurus       21 April – 21 May                      sapphire   

Gemini      22 May – 21 June                      agate   

Cancer      21 June – 22 July                      emerald   

Leo            23 July – 22 August                  onyx   

Virgo         23 August – 22 September     carnelian   

Libra          23 September – 23 October   chrysolite   

Scorpio     24 October – 21 November     beryl   

Sagittarius 22 November – 21 December topaz   

Capricorn  22 December – 21 January      ruby    

Birthday (day of the week) stones

While this word has also been used as synonym of Birth stone (see  above), there is a separate list of assignment according to the day of  the week of the recipient's birth:  

  • Monday: pearl, crystal
  • Tuesday: ruby, emerald
  • Wednesday: amethyst, lodestone
  • Thursday: sapphire, carnelian
  • Friday: emerald, cat's eye
  • Saturday: turquoise, diamond
  • Sunday: topaz, diamond