August birthstone
August's stones are peridot — the olivine green that pharaohs mined on the Egyptian island of Zabargad — and spinel, the red gem long mistaken for ruby in royal regalia (the Black Prince's Ruby and the Timur Ruby are both spinels). They stand for summer light and lasting harmony.
Aventurine
NATMohs 7 / RI 1.544-1.553
Color Change Spinel
NATMohs 8 / RI 1.712-1.730
Green Spinel
NATMohs 8 / RI 1.718
Gray Spinel
NATMohs 8 / RI 1.712-1.720
Synthetic Blue Spinel
SYNMohs 8 / RI 1.725
Synthetic Red Spinel
SYNMohs 8 / RI 1.725-1.740
Tiger's Eye
NATMohs 7 / RI 1.544-1.553
Purple Spinel
NATMohs 8 / RI 1.718
Pink Spinel
NATMohs 8 / RI 1.718
Black Spinel
NATMohs 8 / RI 1.718
Blue Spinel (Natural)
NATMohs 8 / RI 1.718
Peridot
NATMohs 6.5-7 / RI 1.654-1.690
White Spinel
NATMohs 8 / RI 1.712-1.717
Red Spinel
NATMohs 8 / RI 1.718