Birth stones were not discovered ( they all ready existed as gemstones) but instead they were assigned the 12 months of the year to represent that birth month for people who were born during the month.
The first person who discovered stone/rock was The Hunter Gatherers in the stone age.
it must be BC , because later on birth of Jesus Christ (start of AD), the metals were discovered, and there were no stone age remaining on that time.
Mildred Stone's birth name is Mildred I. Stone.
Jaime Stone's birth name is Jaime Stone.
the birth stone is Citrine
Garnet which is my birth stone
Beyonce's birth stone is a sapphire.
The birth stone for January is Garnet.
Robinson Stone's birth name is Stone, Robert W..
Dawn Stone's birth name is Andrea Dawn Stone.
Marianne Stone's birth name is Mary Haydon Stone.
Merritt Stone's birth name is Winfred Merritt Stone.