The Opis charm length is 12mm. Each gemstone is 4mm x 2mm (0.113 CT). Total carat weight for this piece is 0.565 CT. This piece is available is available in cubic zirconia, genuine AA quality white Sapphire, or SI1 Color G genuine diamonds. If you would like to use a different gemstone on this piece, please add a note to the item when you add it to your order, and we will provide a quote for the gemstone change.