bearing in mind that the stones are different cuts (cushion vs diamond cut round), i do see a difference in the colours. the 8.5mm sapphire is the "medium blue" (don't ask me now why i ordered that instead of "top blue" but i'm sure i had a reason!)
but the three are quite different in colour. the blue CZ OMC is more of a denim blue, the medium blue cushion is more of a, well, blue crayon sort of blue, and the Avarra Kashmir is a more purple sort of blue.
i found *a* battery charger so if it works, i'll try to take some comparison pictures tomorrow.
