The origins of birthstones are lost in antiquity; some relate them to the twelve stones mentioned in the Old Testament, on the High Priest's ceremonial breastplate, but different cultures have their own lists. I use the modern, traditional list. Some months have several different stones that are customary.
The stones used in Solomon's Bow are synthetic birthstones. I generally don't offer natural stones, for several reasons:
Natural stones vary widely in cost; amethyst is very cheap, but if you are born in April, we're talking diamond, and a 3mm stone is close to a quarter carat.
Natural stones vary widely in durability. The natural stone for October is an Opal or Tourmaline; for June, Alexandrite or Pearl.
|Month||Traditional Birthstone||Modern Birthstone|
|June||Alexandrite, Emerald||Moonstone, Pearl|
|October||Tourmaline, Aquamarine||Opal, Tourmaline|
|November||Citrine, Topaz||Topaz, Citrine|
|December||Zircon, Ruby||Turquoise, Blue Topaz|