I1, I2, and I3 diamonds have inclusions you can see without magnification.
Journal of Athletic Training. v36 i2 (April-June 2001): 50-59.
I2 - Cloudy diamond with many blemishes and inclusions.
The I1, I2, and I3 grades were added during the 1970s.
By the action of oxidizing agents such as nitric acid, iodine solution, &c., arsenious acid is readily converted into arsenic acid, in the latter case the reaction proceeding according to the equation H3AsO3 +I2 + H2O = H3AsO4 + 2HI.