2.31ct Cushion Cut Teal Spinel 9x7mmSpinel can be red, pink, orange, purple, violet or blue. Red and pink are caused by traces of chromium, orange and purple by chromium and iron and dark blues by traces of iron and cobalt. Spinel used to be offered as a ruby alternative but nowadays it is praised for its own special characteristics. Some spinels display phenomena such as colour change and asterism. Usually, spinels look clean to the naked eye. ; Stone Size (mm): 9. 0x7. 0x4. 6; Carat