Birthstones by Month

There are multiple birthstones by month lists and their interpretations. Arguably, the four most distinctive ones would be by birth month, guardian angel, special apostle, and sign of zodiac birthstone lists. These lists provide good options and the choice is ultimately yours!

Most if not all birthstone lists are based on either New Jerusalem foundation gems mentioned in Revelation or on Aaron's breastplate gemstones described in Exodus. 

Most likely, the 1st mentionings of birthstones go back to the 1st and the 5th centuries A.D. Both Flavius Josephus and St Jerome declared a clear connection between the breastplate of the high priest and the 12 months of the year as well as the 12 zodiac signs. 
Josephus wrote that there were “twelve stones upon the Breastplate, extraordinary in largeness and beauty: and they were an ornament not to be purchased by men because of their immense value”.

The breastplate of the high priest in Jewish tradition was treated with deepest respect, and gems set in it were believed to be emblematic of many things. Birthstone names in some cases aren't identical to those given in the book of Exodus most likely due to different versions of translation from Hebrew and Greek. The original order in which the foundation stones are given in Revelation determine the order of birthstones starting from March - the month of spring Equinox.

Despite the early mentionings of the birthstones, documented wearing of them as birth symbols or birth gems dates as late as the 16th century. The tradition originates from either Poland or Germany. It is also believed that Arabian astrologists may have originally brought the idea to Europe in the 15th century.

The 12 foundation stones mentioned in the Revelation of St. John are directly associated with the 12 apostles. The assignment of each gem to the respective apostle happened at a later time, around the 8th century. Besides this, even later, we would see the 12 angels associated with the months and signs of zodiac. Guardian angels birthstones are also commonly called ‘talismanic gems’. 

As we already know, there were multiple birthstone by month lists circulating, and in an attempt to unify it in August 1912 in Kansas City the National Association of Jewelers agreed on the standard birthstone by birth month list, which has been revised in 2019  by the Gemological Institute of America (GIA). Great Britain uses a list of birthstones similar to the GIA one with some small changes.

Astrological calendars and zodiac signs came to the western culture from ancient Babylon. People were convinced that they strengthened the influence of their zodiacal sign by wearing the appropriate birthstone. It was done to achieve the transmission of stellar influences passed through the gem. Zodiacal birthstone list is arguably the most disputed out of all, and I made a choice of the zodiac sign birthstone list based on the old Spanish list from the beginning of the 17th century which was in turn very closely based on the ancient list of the Arabian astrologists. Minor changes have been performed.