<Tr> <Td> August </Td> <Td> sardonyx, carnelian, moonstone, topaz </Td> <Td> sardonyx, peridot </Td> <Td> peridot, spinel </Td> <Td> peridot, sardonyx </Td> </Tr> <Tr> <Td> September </Td> <Td> chrysolite </Td> <Td> sapphire </Td> <Td> sapphire </Td> <Td> sapphire, lapis lazuli </Td> </Tr> <Tr> <Td> October </Td> <Td> opal, aquamarine </Td> <Td> opal, tourmaline </Td> <Td> opal, tourmaline </Td> <Td> opal </Td> </Tr> <Tr> <Td> November </Td> <Td> topaz, pearl </Td> <Td> topaz </Td> <Td> topaz, citrine </Td> <Td> topaz, citrine </Td> </Tr>

Where did the concept of birthstones come from